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diff --git a/45639-8.txt b/45639-8.txt new file mode 100644 index 0000000..c085d83 --- /dev/null +++ b/45639-8.txt @@ -0,0 +1,7178 @@ +The Project Gutenberg eBook, Buffon's Natural History, Volume III (of 10), +by Georges Louis Leclerc, Comte de Buffon, Translated by James Smith Barr + + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + + + + + +Title: Buffon's Natural History, Volume III (of 10) + Containing a Theory of the Earth, a General History of Man, of the Brute Creation, and of Vegetables, Minerals, &c. &c. + + +Author: Georges Louis Leclerc, Comte de Buffon + + + +Release Date: May 12, 2014 [eBook #45639] + +Language: English + +Character set encoding: ISO-8859-1 + + +***START OF THE PROJECT GUTENBERG EBOOK BUFFON'S NATURAL HISTORY, VOLUME +III (OF 10)*** + + +E-text prepared by Chris Curnow, Tom Cosmas, and the Online Distributed +Proofreading Team (http://www.pgdp.net) from page images generously made +available by Internet Archive (https://archive.org) + + + +Note: Project Gutenberg also has an HTML version of this + file which includes the original illustrations. + See 45639-h.htm or 45639-h.zip: + (http://www.gutenberg.org/files/45639/45639-h/45639-h.htm) + or + (http://www.gutenberg.org/files/45639/45639-h.zip) + + + Images of the original pages are available through + Internet Archive. See + https://archive.org/details/buffonsnaturalhi03buff + + +Transcriber's note: + + Text enclosed by underscores is in italics (_italics_). + + + + + + _Barr's Buffon._ + + Buffon's Natural History, + + CONTAINING + + A THEORY OF THE EARTH, + A GENERAL + _HISTORY OF MAN_, + OF THE BRUTE CREATION, AND OF + VEGETABLES, MINERALS, + _&c._ _&c._ + + FROM THE FRENCH. + + WITH NOTES BY THE TRANSLATOR. + + IN TEN VOLUMES. + + VOL. III. + + London: + PRINTED FOR THE PROPRIETOR, + AND SOLD BY H. D. SYMONDS, PATERNOSTER-ROW. + + 1807. + + T. Gillet, Printer, Wild-Court. + + + + + CONTENTS + + OF + + THE THIRD VOLUME. + + + _Page_ + + History of Animals 1 + + Chap. VI. _Experiments on the Method of Generation_ 81 + + Chap. VII. _Comparison of my Observations with those + of Leeuwenhoek_ 134 + + Chap. VIII. _Reflections on the preceding Experiments_ 159 + + Chap. IX. _Varieties on the Generation of Animals_ 208 + + Chap. X. _On the Formation of the Foetus_ 226 + + Chap. XI. _On the Expansion, Growth, and Delivery of + the Foetus_ 260 + + _Recapitulation_ 309 + + + History of Man. + + Chap. I. _Of the Nature of Man_ 317 + + Chap. II. _Of Infancy_ 334 + + + +_Directions for placing the Plates._ + + + Page 88, Fig. 1, 2, 3, 4, 5, 6. + 106, Fig. 7, 8, 9, 10, 11, 12. + 140, Plate III. + 148, Plate IV. + + + + +BUFFON'S + +NATURAL HISTORY. + + + + +_HISTORY OF ANIMALS._ + + +Aristotle admits, with Plato, of final and efficient causes. These +efficient causes are sensitive and vegetative souls, that give form to +matter which, of itself, is only a capacity of receiving forms; and +as in generation the female gives the most abundant matter, and it +being against his system of final causes to admit that what one could +effect should be performed by many, he concludes, that the female +alone contains the necessary matter to generation; and, as another of +his principles was, that matter itself is unformed, and that form is +a distinct being from matter, he affirmed that the male furnished the +form, and, consequently, nothing belonging to matter. + +Descartes, on the contrary, who admitted but a few mechanical +principles in his philosophy, endeavoured to explain the formation +of the foetus by them, and thought it in his power to comprehend, +and make others understand, how an organized and living being could +be made by the laws of motion alone. His admitted principles differed +from those used by Aristotle; but both, instead of examining the thing +itself, without prepossession and prejudice, have only considered it +in the point of view relative to their systems of philosophy, which +could not be attended with a successful application to the nature of +generation, because it depends, as we have shewn, on quite different +principles. Descartes differs still more from Aristotle, by admitting +of the mixture of the seminal liquor of the two sexes; he thinks both +furnish something material for generation, and that the fermentation +occasioned by the mixture of these two seminal liquors causes the +formation of the foetus. + +Hippocrates, who lived under Perdicas, a considerable time before +Aristotle, established an opinion, which was adopted by Galen, and a +great number of physicians who followed him; his opinion was, that the +male and female had each a prolific fluid, and supposed, besides, that +there were two seminal fluids in each sex, the one strong and active, +the other weak and inactive.[A] That a mixture of the two strongest +fluids produce a male child, and of the two weakest a female; so +that, according to him, they each contain a male and a female seed. +He supports this hypothesis by the following circumstance; that many +women, who produce only girls by their first husbands, have produced +boys by a second; and that men, who have had only girls by their first +wives, have had boys by others. It appears to me, that if even this +circumstance could be well established, it would not be necessary +to give to the male and female two kinds of seminal liquor for an +explanation; because it may easily be conceived, that women, who have +brought forth only girls by their first husbands, and produced boys +with other men, were only those who furnished more particles proper +for generation with their first husband than with the second; or that +the second husband furnished more particles proper for generation +with the second wife than with the first; for when, in the instant of +conception, the organic molecules of the male are more abundant than +those of the female, the result will be a male, and when those of +the female abounds a female will be produced; nor is it in the least +surprising that a man should have a disadvantage in this respect with +some women, while he will have a superiority over others. + +[A] See Hippocrates, lib. de Genitura, page 129, & lib. de dięta, page +198, Lugd. Bat. 1665, vol. I. + +This great physician supposes, that the seed of the male is a secretion +of the strongest and most essential parts of all that is humid in the +human body; and he thus explains how this secretion is made: "Venę +& nervi, he says, ab omni corpore in pudendum vergunt, quibus dum +aliquantulum teruntur & calescunt ac implentur, velut pruritus incidit, +ex hoc toti corpori voluptas ac caliditas accidit; quum vero pudendum +teritur & homo movetur, humidum in corpore calescit ac diffunditur, +& a motu conquassatur ac spumescit, quemadmodum alii humores omnes +conquassati spumescunt. + +"Sic autem in homine ab humido spumescente id quod robustissimum est ac +pinguissimum secernitur, & ad medullam spinalem venit; tendunt enim in +hanc ex omni corpore vię, & diffundunt ex cerebro in lumbus ac in totum +corpus & in medullum; & ex ipsa medull proacedunt vię, ut & ad ipsum +humidum perferatur & ex ipsa secedat; postquam autem ad hanc medullam +genitura pervenerit, procedit ad renes, hac enim via tendit per venas, +& si renes fuerint exulcerati, aliquando etiam sanguis defertur: a +renibus autem transit per medois testes in pudendum, proce dit autem +non qua urina, erum alia ipsi via est illi contigua, &c."[B] + +[B] See Fęsius's Translation, vol. I. page 129. + +Anatomists will no doubt discover that Hippocrates is not correct +in tracing the road of the seminal liquor; but that does not affect +his opinion, that the semen comes from every part of the body, and +particularly the head, because, he says, those whose veins have been +cut which lie near the ears only bring forth a weak, and very often an +unfertile semen. The female has also a seminal fluid, which she emits, +sometimes within the matrix, and sometimes without, when the internal +orifice is more open than it should. The semen of the male enters into +the matrix, where it mixes with that of the female; and as each has +two kinds of fluid, the one strong and the other weak, if both furnish +their strong, a male will be the result, and if their weak, a female; +and if in the mixture there are more particles of the male liquor than +the female, then the infant will have a greater resemblance to the +father than to the mother, and so on the contrary. It might here be +asked Hippocrates what would happen when the one furnished its weak +semen and the other its strong? I cannot conceive what answer he could +make, and that alone is sufficient to cause his opinion of two seeds in +each sex to be rejected. + +In this manner then, according to him, the formation of the foetus is +made: the seminal fluids first mix in the matrix, where they gradually +thicken by the heat of the body of the mother; the mixture receives and +attracts the spirit of the heat, and when too warm part of the heat +flies out, and the respiration of the mother sends a colder spirit in; +thus alternatively a cold and a hot spirit enter the mixture, which +give life, and cause a pellicle to grow on the surface, which takes a +round form, because the spirits, acting as a centre, extend it equally +on all sides. "I have seen, says this great man, a foetus of six days +old; it was a ball of liquor surrounded with a pellicle; the liquor +was reddish, and the pellicle was spread over with vessels, some red +and others white, in the midst of which was a small eminence, which I +thought to be the umbilical vessels, by which the foetus receives +nourishment and the spirit of respiration from the mother. By degrees +another pellicle is formed, which surrounds the first; the menstrual +blood, being suppressed, abundantly supplies it with nutriment, and +which coagulates by degrees, and becomes flesh; this flesh articulates +itself in proportion as it grows, and receives its form from the +spirit; each part proceeds to take its proper place; the solid +particles go to their respective situations and the fluid to theirs: +each matter seeks for that which is most like itself, and the foetus +is at length entirely formed by these causes and these means." + +This system is less obscure and more reasonable than that of Aristotle, +because Hippocrates endeavours to explain every matter by particular +reasons: he borrows from the philosophy of his times but one single +principle, which is, that heat and cold produce spirits, and that those +spirits have the power of ordering and arranging matter. He has viewed +generation more like a physician than a philosopher, while Aristotle +has explained it more like a metaphysician than a naturalist; which +makes the defects of Hippocrates's system particular and less apparent, +while those of Aristotle's are general and evident. + +These two great men have each had their followers; almost all the +scholastic philosophers, by adopting Aristotle's philosophy, received +his system of generation, while almost every physician followed +the opinion of Hippocrates; and seventeen or eighteen centuries +passed without any thing new being said on the subject. At last, at +the restoration of literature, some anatomists turned their eyes +on generation, and Fabricius Aquapendente was the first who made +experiments and observations on the impregnation and growth of the eggs +of a fowl. The following is the substance of his observations. + +He distinguished two parts in the matrix of a hen, the one superior +and the other inferior. The superior he calls the Ovarium, which is +properly no other than a cluster of small yellow eggs of a round form, +varying in size from the bigness of a mustard-seed to that of a large +nut or medlar. These small eggs are fastened together by one common +pellicle, and form a body which nearly resembles a bunch of grapes. +The smallest of these eggs are white, and they take another colour in +proportion as they increase. + +Having examined these eggs immediately after the communication of the +cock, he did not perceive any remarkable difference, nor any of the +male semen in any one of these eggs; he therefore supposed that every +egg, and the ovarium itself, became fruitful by a subtle spirit, which +came from the semen of the male; and he says, that in order to secure +this fecundating spirit, nature has placed at the external orifice of +the vagina of birds a kind of net-work or membrane, which permits, like +a valve, the entrance of this seminal spirit, but at the same time +prevents it from re-issuing or evaporating. + +When the egg is loosened from the common pellicle, it descends by +degrees through a winding passage into the internal part of the matrix. +This passage is filled with a liquor nearly similar to the white of +an egg; it is also in this part that the eggs begin to be surrounded +with this white liquor, with the membrane which occasions it, the two +ligaments (_chalazę_) which passes over the white, and connects it +with the yolk and shell, which are formed in a very short time before +they are laid. These ligaments, according to Fabricius, is the part of +the egg fecundated by the seminal spirit of the male; and it is here +where the foetus first begins to form. The egg is not only the true +matrix, that is to say, the place of the formation of the chick, but +it is from the egg all generation depends. The egg produces it as the +agent: it supplies both the matter and the organs; the ligaments are +the substance of formation; the white and the yolk are the nutriment, +and the seminal spirit of the male is the efficient cause. This +spirit communicates to the ligaments at first an alterative faculty, +afterwards a formative, and lastly the power of augmentation, &c. + +These observations of Fabricius have not given us a very clear +explication of generation. Nearly at the same time as this anatomist +was employed in these researches, towards the middle of the sixteenth +century, the famous Aldrovandus[C] also made observations on eggs; but +as Harvey judiciously observes, he followed Aristotle much closer than +experiment. The descriptions he gives of the chicken in the egg are +not exact. Volcher Coiter, one of his scholars, succeeded much better +in his enquiries; and Parisanus, a physician of Venice, having also +laboured on this subject, they have each given a description of the +chicken in the egg, which Harvey prefers to any other. + +[C] See his Ornithology. + +This famous anatomist, to whom we are indebted for the discovery of the +circulation of the blood, has composed a very extensive treatise on +generation; he lived towards the middle of the last century, and was +physician to Charles I. of England. As he was obliged to follow this +unfortunate prince in his misfortunes, he lost what he had written on +the generation of insects among other papers, and he composed what he +has left us on the generation of birds and quadrupeds from his memory. +I shall concisely relate his observations, his experiments, and his +system. + +Harvey asserts that man and every animal proceed from an egg; that the +first produce of conception in viviparous animals is a kind of an egg, +and that the only difference between viviparous and oviparous is, that +the foetus of the first take their origin, acquire their growth, and +arrive at their entire expansion in the matrix; whereas the foetus of +oviparous animals begins to exist in the body of the mother, where they +are merely as eggs, and it is only after they have quitted the body of +the mother that they really become foetuses; and we must remark, says +he, that in oviparous animals, some hold their eggs within themselves +till they are perfect, as birds, serpents and oviparous quadrupeds; +others lay their eggs before they are perfect, as fish, crustaceous, +and testaceous animals. The eggs which these animals deposit are only +the rudiments of real eggs, they afterwards acquire bulk and membranes, +and attract nourishment from the matter which surrounds them. It is the +same, adds he, with insects, for example, and caterpillars, which only +seem imperfect eggs, which seek their nutriment, and at the end of a +certain time arrive to the state of chrysalis, which is a perfect egg. +There is another difference in oviparous animals: for fowls and other +birds have eggs of different sizes, whereas fish, frogs, &c. lay them +before they are perfect, have them all of the same size; he indeed +observes, that in pigeons, who only lay two eggs, all the small eggs +which remain in the ovarium are of the same size, and it is only the +foremost two which are bigger than the rest. It is the same, he says, +in cartilaginous fish, as in the thornback, who have only two eggs +which increase and come to maturity, while those which remain in the +ovarium are, like those in fowls, of different sizes. + +He afterwards makes us an anatomical exposition of the parts necessary +to generation, and observes, that in all birds the situation of the +anus and vulra are contrary to the situation of those parts in other +animals; the anus being placed before and the vulra behind;[D] and +with respect to the cock, and all small birds, that they generate by +external friction, having in fact no intermission nor real copulation; +with male ducks, geese, and ostriches, it is evidently otherwise. + +[D] Most of these articles are taken from Aristotle. + +Hens produce eggs without the cock, but in a very small number, and +these eggs, although perfect, are unfruitful: he does not agree with +the opinion of country people, that two or three days cohabitation +with the cock is sufficient to impregnate all the eggs a hen will lay +within the year, but admits that he separated a hen from a cock for the +space of twenty days, and that all the eggs she laid during that space +were fecundated. While the egg is fastened to the ovarium, it derives +its nutriment from the vessel of the common pellicle. But as soon as +it is loosened from it, it derives the white liquor which fills the +passages in which it descends, and the whole, even to the shell, is +formed by this mode. + +The two ligaments (_chalazę_) which Aquapendente looks on as the shoot +produced by the seed of the male, are found in the infecund eggs +which the hen produces without the communication with the cock, as +in those which are impregnated: and Harvey very judiciously remarks, +that those parts do not proceed from the male, and are not those which +are fecundated; the fecundated part of an egg is a very small white +circle which is on the membrane that covers the yolk, and forms there +a small spot, like a cicatrice, about the size of a lentil. Harvey +also remarks, that this little cicatrice is found in every fecund or +infecund egg, and that those who think it is produced by the seed of +the male are deceived. It is of the same size and form in fresh eggs, +as in those which have been kept a long time; but when we would hatch +them, and when the egg receives a sufficient degree of heat, either by +the hen, or artificially, we presently see this small spot increase and +dilate nearly like the sight of the eye. This is the first change, and +is visible at the end of a few hours incubation. + +When the egg has undergone a proper warmth for twenty-four hours, +the yolk, which was before in the centre of the shell, approaches +nearer to the cavity at the broad end; this cavity is increased by the +evaporation of the watery part of the white, and the grosser part sinks +to the small end. The cicatrice, or speck, on the membrane of the yolk, +rises with it to the broad end, and seems to adhere to the membrane +there: this speck is then about the bigness of a small pea, in the +middle of it a white speck is discernible, and many circles, of which +this point seems to form the centre. + +At the end of the second day these circles are larger and more +visible; the streak also appears divided by these circles into two, +and sometimes three parts of different colours; a small protuberance +also appears on the external part, and nearly resembles a small eye, +in the pupil of which there is a point, or little cataract; between +these circles a clear liquor is contained by a very delicate membrane, +and the speck now appears more to be placed in the white than on the +membrane of the yolk. On the third day the transparent liquor is +considerably increased, as is also the small membrane which surrounds +it. The fourth day, a small streak of purple-coloured blood is observed +at the circumference of the speck or ball, at a little distance from +the centre of which a point may be seen of a blood colour, and which +beats like a heart. It appears like a small spark at each diastole, and +disappears at each systole; from this animated speck issue two small +blood vessels, which these small vessels throw out as branches into +this liquor, all of which come from the same point, nearly in like +manner as the roots of a tree shoot from the trunk. + +Towards the end of the fourth day, or at the beginning of the fifth, +the animated speck is so much increased as to appear like a small +bladder filled with blood, and by its contractions and dilations +is alternatively filled and emptied. In the same day this vessel +very distinctly appears to divide into two parts, each of which +alternatively impel and dilute the blood in the same manner. Around +the shortest sanguinary vessel which we have spoken of a kind of cloud +is seen, which, although transparent, renders the sight of this vessel +more obscure; this cloud constantly grows thicker and more attached +to the root of the blood vessel, and appears like a small globe: this +small globe lengthens and divides into three parts, one of which is +globular, and larger than the other two; the head and eyes now begin to +appear, and at the end of the fifth day, the place for the vertebra is +seen in the remainder part of this globe. + +The sixth day the head is seen more clearly, the outlines of the eyes +now appear, the wings and thighs lengthen, and the liver, lungs, and +beak, are distinctly observed; the foetus now begins to move and +extend its head, although it has as yet only the internal viscera; for +the thorax, abdomen, and all the external coverings of the fore part, +of the body are wanting. At the end of this day, or at the beginning +of the seventh, the toes appear, the chick opens and moves its beak, +and the anterior parts of the body begin to cover the viscera; on the +seventh day the chicken is entirely formed, and from this time until +it comes out of the egg, nothing happens but only an expansion of those +parts it acquired within these first seven days: at the fourteenth or +fifteenth day the feathers appear, and at the twenty-first it breaks +the shell with its beak, and procures its enlargement. + +These observations of Harvey appear to have been made with the greatest +exactness; nevertheless we shall point out how imperfect they are, +and that he has fallen himself into the error he reproaches others +with, making experiments to support his favourite hypothesis, that +the heart was the animated speck which first appeared; but before we +proceed on this matter, it is but just to give an account of his other +observations, and of his system. + +It is well known that Harvey made many experiments on hinds and does. +They receive the male towards the middle of September: a few days after +copulation the horns of the matrix become thicker, and at the same time +more lax. In each of the cavities five carunculas appear. Towards the +26th or 28th of the above month the matrix thickens still more, and the +five carunculas are swelled nearly to the shape and size of a nurse's +nipple; by opening them, an infinity of small white specks are found. +Harvey pretends to have remarked, that there was neither then, nor +immediately after copulation, any alteration or change in the ovarium, +and that he has never been able to find a single drop of the seed of +the male in the matrix, although he has made many researches for that +purpose. + +Towards the end of October, or beginning of November, when the +females separate from the males, the thickness of the horns begins +to diminish, the internal surfaces of their cavities are swelled, +and appear fastened together; the carunculas remain, and the whole, +which resembles the substance of the brain, is so soft that it cannot +be touched. Towards the 13th or 14th of November, Harvey says, that +he perceived filaments, like the threads of a spider's web, which +traversed the cavities of the horns and the matrix itself: these +filaments shoot out from the superior angle of the matrix, and by +their multiplication form a kind of membrane, or empty tunic; a day +or two after this tunic is filled with a white, aqueous and glutinous +matter, which adheres to the matrix by a kind of mucilage; and in the +third month this tunic, or pouch, contains an embryo about the breadth +of two fingers long, and another internal pouch, called the amnios, +containing a transparent crystalline liquor, in which the foetus +swims. The foetus at first was but an animated speck, like that in +the egg of a fowl. All the rest is performed in the same manner as that +related of the chick; the only difference is in the eyes, which appears +much sooner in the fowl than in the deer. The animated speck appears +about the 19th or 20th of November, a day or two after which the oblong +body, which contains the foetus, is seen; in six or seven days more +it is so much formed that the sex and limbs may be distinguished; but +the heart and viscera are yet uncovered, and it is two days more before +the thorax and the abdomen cover them, which is the last work and +completion of the edifice. + +From these observations upon hens and deer, Harvey concludes, that +all female animals have eggs, that in these eggs a separation of a +transparent crystalline liquor contained in the amnios is made, and +that another external pouch, the chorion, contains the whole liquors of +the egg; that the first thing which appears in the crystalline liquor +is the sanguinary and animated spirit; in a word, that the formation of +viviparous animals is made after the same manner as oviparous; and he +explains the generation of both as follows. + +Generation is the work of the matrix, in which no seed of the male +ever enters; the matrix conceives by a kind of contagion, which the +male liquor communicates to it, nearly as the magnet communicates +its magnetic virtue to steel. This male contagion not only acts upon +the matrix but over all the female body, which is wholly fecundated, +although the matrix only has the faculty of conception, as the brain +has the sole faculty of conceiving ideas. The ideas conceived by the +brain, are like the images of the objects transmitted by the senses; +and the foetus, which may be considered as the idea of the matrix, is +like that which produces it. This is the reason that a child has a +resemblance to its father, &c. + +I shall not follow this anatomist any farther; what I have mentioned +is sufficient to judge of his system; but we have some remarks to make +on his observations. He has given them in a manner most likely to +impose; seems to have often repeated his experiments, and to have taken +every necessary precaution to avoid deception; from which it might +be imagined he had seen all he writes upon, and observed them with +the greatest accuracy. Nevertheless, I perceive both uncertainty and +obscurity in his descriptions; his observations are related chiefly on +memory; and although he often says the contrary, Aristotle appears to +have been his guide more than experience; for he has only seen in eggs +what Aristotle has before mentioned; and that most of his observations +which may be deemed essential had been made before him, we shall be +perfectly convinced if we pay a little attention to what follows: + +Aristotle knew that the ligaments (Chalazę) were of no service to the +generation of the chicken. "Quę ad principium lutei grandines hęrent, +nil conferunt ad generationem, ut quidam suspicantur."[E] Parisanus, +Volcher, Coiter, Aquapendente, and others, remarked the cicatrice as +well as Harvey: Aquapendente supposed it of no use; but Parisanus +pretended that it was formed by the male semen, or at least that the +white speck in the middle of the cicatrice was the seed of the male +which would produce the chicken. "Est-que, says he, illud galli semen +alba & tenuissima tunica abductum, quod substat duabus communibus +toti ovo membranis, &c." Therefore the only discovery which properly +belongs to Harvey is, his having observed that this cicatrice is found +in infecund as well as fecundated eggs; for others had observed, like +him, the dilation of the circles, and the growth of the white speck; +and it appears that Parisanus had seen it much better; this is all +which he remarks in the two first days of incubation; and what he says +of the third day, is only a repetition of Aristotle's words. [F]"Per id +tempus ascendit jam vetellus ad superiorem partem ovi acutiorem, ubi +& principium ovi est & foetus excluditur; corque ipsum apparet, in +albumine sanguinei puncti, quod punctum salit & movet sese instar quasi +animatum; ab eo meatus venarum specie duo, sanguinei pleni, flexuosi, +qui, crescente foetu, feruntur in utramque tunicam ambientem, ac +membrana sanguineas fibras habens eo tempore albumen continet sub +meatibus illis venarum similibus; ac paulo post discernitur corpus +pufillum initio, ommino & candidum, capite conspicuo, atque in eo +oculis maxime turgidis qui diu sic permanent, sero enim parvi fiunt ac +considunt. In parte autem corporis inferiore, nullum extat membrum per +initia, quod respondeat superioribus. Meatus autum illi qui a corde +prodeunt, alter ad circumdantem, membranam tendit, alter ad luteum, +officio umbilici." + +[E] Hist. Anim. lib. vi. cap. 2. + +[F] Hist. Anim. lib. vi. cap. 4. + +Harvey attacks Aristotle for saying that the yolk ascends towards the +small end of the egg, and concludes, that he had not seen any thing +himself, but had apparently received his information from some good +observer of Nature. Harvey was wrong in thus reproaching Aristotle, and +in asserting that the yolk always ascends towards the broad end of the +egg, for that depends on the position of the egg during the time of +incubation, for the yolk always ascends to the uppermost part, as being +lighter than the white, whether it be to the broad or the small end. +William Langley, a physician at Dordrecht, who made observations on the +hatching of eggs, in 1655, twenty years before Harvey, was the first +who made this remark.[G] + +[G] See Wm. Langley Observ. edę a justo Schradero, Amst. 1674. + +But to return to the passage we have quoted. By that we see that the +crystalline liquor, the animated speck, the two circles, the two +blood vessels, &c. are described by Aristotle precisely as Harvey +had seen them. This anatomist also pretends that the animated speck +is the heart, that this heart is formed the first, and that the +viscera and other parts are joined afterwards. All this has been +spoken of by Aristotle, and seen by Harvey, and nevertheless it is +not conformable to truth. To be assured of this we need only repeat +the same experiments on eggs, or only read with attention those of +Malpighius,[H] which were made about 40 years after those of Harvey. + +[H] Malpighii pullus in ovo. + +This excellent observer of Nature examined, with attention, the +cicatrice, which is the essential part of the egg; he found it was +large in all impregnated eggs, and small in those which were not +impregnated; and he discovered in eggs which had never been sat upon, +that the white speck, spoken of by Harvey as the first which becomes +animated, is a small pouch or ball, which swims in a liquor inclosed +by the first circle, and in the middle of this ball he observed the +embryo. The membrane of this small pouch, which is the amnios, being +very thin and transparent, permitted him easily to see the foetus +it surrounded. Malpighius, with reason, concludes, from this first +observation, that the foetus exists in the egg before incubation, and +that its first outlines are then very strong. It is not necessary to +point out how opposite this experiment is to the opinion of Harvey, +for he saw nothing of a form for the two first days of incubation, and +it was the third day before the sign of the foetus appears, which is +the animated speck: whereas according to Malpighius, the outlines of +the foetus exist in the egg before incubation has commenced. + +After being assured of this important matter, Malpighius examined, with +like attention, the cicatrice of unimpregnated eggs, which, as we have +observed, is smaller than those which have been impregnated; it has +often irregular circumscriptions, and sometimes differs in different +eggs. Near its centre, instead of the ball that encloses the foetus, +there is a globular mole, which does not contain any thing organized, +and which being opened does not present any thing formed or arranged, +but only some appendages filled with a thick but transparent fluid; and +this unshapen mass is surrounded with many concentric circles. + +After six hours incubation the cicatrice is considerably dilated, +and the ball formed by the amnios is easily discovered; this ball is +filled with a liquor, in the middle of which the head of the chicken +and back-bone are distinctly seen. In about six hours more the little +animal is seen more distinctly; in another six hours the head is +grown larger, and the spine lengthened; and at the end of twenty-four +hours the neck begins to lengthen, the vertebrę of the back appears +of a white colour, and the head to turn to one side. The vertebrę are +disposed on each side of the spine, like small globules; and almost +at the same time the small wings begin to shoot, and the head, neck, +and breast are lengthened. After thirty hours nothing new appears, +but every part of the little animal is considerably increased, +especially the _amnios_. Around this membrane the umbilical vessels +are seen of a darkish colour. At the end of thirty-eight hours, the +chicken being grown much larger, its head is large, and in which +are distinguished three vessels surrounded with membranes, which +also cover the back bone, through which the vertebrę are still seen. +In forty hours, continues Malpighius, it was wonderful to see the +chicken alive, floating in the liquor; the back bone was increased, +the head was turned on one side, the vesicles of the brain were less +apparent, the first outlines of the eyes appeared, the heart beat, and +the circulation of the blood was begun. Malpighius then gives the +description of the vessels and course of the blood, and reasonably +supposes that, though the heart does not beat before thirty-eight or +forty hours incubation, it still existed before that time, like the +other parts of the chicken; but on examining the heart in a dark room, +he discovered not the least glimpse of light to proceed from it, as +Harvey insinuates. + +At the end of two days the chicken is seen floating in the liquor of +the amnios; in which the head, composed of vesicles, is turned on one +side; the back bone and vertebrę are lengthened; the heart, which then +hung out of the breast, beat three times; for the fluid it contains +is impelled into the ventricles of the heart, from thence into the +arteries, and afterwards into the umbilical vessels. He remarks, that +having separated the chick from the white of the egg, the motion of +the heart still continued for a whole day. After two days and fourteen +hours, or sixty-two hours of incubation, the chicken, although grown +stronger, remained with its head bent downwards in the liquor, +contained by the amnios; the veins and arteries were seen among the +vessels of the brain; the lineaments of the eyes, and the spinal +marrow, also appear extending the length of the vertebrę. + +At the end of the third day the head of the chicken appeared crooked; +besides the eyes five vessels were seen in the head filled with a +liquid matter; the first outlines of the wings and thighs were to be +distinguished, and the body began to gather flesh; the pupil of the +eye, and also the crystalline and vitreous humour were discernible. At +the fourth day the vesicles of the brain were nearer each other; the +eminences of the vertebrę were more prominent, the wings and thighs +assumed a greater solidity as they increased in length; the whole body, +covered with a jelly-like flesh, was now surrounded within the body by +a thin membrane, and the umbilical vessels that unite the animal to +the yolk, appeared to come from the abdomen. On the fifth and sixth +days the vesicles of the brain began to be covered; the spinal marrow, +divided into two parts, began to take solidity and stretch along the +trunk; the wings and thighs lengthened; the feet began to spread; the +belly was closed up and tumid; the liver was distinctly seen, and +appeared of a dusky white; the ventricles of the heart were discerned +to beat very distinctly; the body of the chicken was covered with a +skin, and the traces of the feathers were visible; the seventh day +the head appeared very large, the brain was entirely covered with its +membranes; the beak began to appear betwixt the eyes, and the wings, +the thighs, and the legs had acquired their perfect figure. + +I shall not follow Malpighius any farther, as the remainder relates +only to the expansion of the parts till the twenty-first day, when the +chicken breaks the shell with its beak; though before that time it is +heard to chirrup in its imprisonment. The heart is the last part which +receives its proper form, for it is eleven days before the arteries +are seen to join, and the ventricles become perfectly conformable and +united. + +We are now in a condition to judge of the value of Harvey's experiments +and observations. There is great appearance this anatomist did not +make use of a microscope, which in fact was not brought to perfection +in his days, or he would not have asserted there was no difference +between the cicatrice of an impregnated and an unimpregnated egg; he +would not have said the seed of the male produced no alteration in +the egg, especially in the cicatrice; he would not have affirmed that +nothing was perceptible till the third day, that the animated speck was +the first that appeared, and into which the white speck was changed. +He would have seen that the white speck was a ball which contained the +whole apparatus of generation, and that every part of the foetus are +there from the moment the hen has connection with the cock. He would +also have learnt, that without this connection it contains only an +unshapen mass, which could never become animated, because in fact it is +not organized like an animal, and because it is only when this mass, +which we must look upon as an assemblage of the organic particles of +the female semen, is penetrated by the organic particles of the male +semen, that there results from it an animal, which is formed at the +moment, but whose motion is imperceptible till the end of forty hours +after: he would not have asserted that the heart is first formed, and +that the other parts are joined to it by a juxta-position, since it +is evident from Malpighius's observations, that the outlines of every +part are all immediately formed, but only appear in proportion as they +dilate; on the whole, if he had seen what Malpighius saw, he would not +have affirmed that no impression of the male seed remained in the eggs, +and that it was only by contagion that they are fecundated, &c. + +It is also just to remark, that what Harvey has said on the parts of +the generation of a cock is not exact; he asserts that the cock has no +genital member, and that there is no intromission; nevertheless it is +certain that this animal, instead of one has two, and that they both +act at the same time, and which action is a very strong compression, if +not a true copulation;[I] and it is by this double organ that the cock +emits the seminal liquor into the matrix of the hen. + +[I] See Reyn. Graaf, page 242. + +Let us now compare the experiments made by Harvey on hinds with those +of De Graaf on doe rabbits; we shall find that although De Graaf +supposes, with Harvey, that all animals proceed from eggs, yet there is +a great difference in the mode which these two anatomists have observed +in the first steps of formation, or rather expansion, of the foetuses +of viviparous animals. + +After having exerted every effort to establish, by reasons drawn from +comparative anatomy, that the testicles of viviparous females are real +ovaries, De Graaf explains how the eggs are loosened from the ovaries +and fall into the horns of the matrix; he then relates what he observed +in a rabbit, which he dissected half an hour after copulation. The +horns of the matrix, he says, were more red than before, but no other +change in the rest of the parts: there was also no appearance of any +male seed, neither in the vagina, matrix, nor horns of the matrix. + +Having dissected another six hours after copulation he observed the +follicules, or coats, which he supposes contained the eggs in the +ovary, ware become red, but found no male seed either in the ovaria or +elsewhere. He dissected another twenty-four hours after copulation, +and remarked in one ovarium three, and in the other five follicules +that were changed, the transparency being become dark and red. In one +dissected twenty-seven hours after copulation he perceived the horns +of the womb had become more red and strictly embraced the ovaries. In +another, that he opened forty hours after copulation, he found in one +of the ovaries seven, follicules, and in the other three that were +changed. Fifty-two hours after copulation he examined another and +found one follicle changed in one of the ovaries and four in another, +and having opened these follicules he found a glandular liquor, in the +middle of which there was a small cavity, where he did not perceive +any liquor, which made him suppose that the transparent liquor, +commonly contained in the follicules, and which, he says, is enclosed +in its own membranes, might have been separated by a kind of rupture: +he searched after this matter in the passages, and in the horns of +the matrix themselves, but he found none; he only perceived that the +internal membrane of the horns of the matrix was very much swelled. In +another, dissected three days after copulation, he observed that the +superior extremity of the passage, which communicates with the horns +of the matrix, strictly embraced the ovaries; and having separated it +he perceived three follicules, longer and harder than usual. After +searching with the greatest attention the passages above-mentioned he +found in the right passage one egg, and in the right horn of the matrix +two more, not bigger than a grain of mustard-seed: those little eggs +were each closed in double membranes, and the inner one was filled +with a very limpid liquor. Having examined the other ovarium he found +four follicules that were changed, three of which were white and had a +little liquor within them; but the fourth was of a darker colour, and +contained no liquor, which made him judge that from this the egg had +been separated. Pursuing his enquiries he found an egg in the superior +extremity of the other horn, and exactly like those he had discovered +in the right one. He says that the eggs which are separated from the +ovary are ten times smaller than those which are fastened to it; and +he thinks that this difference is occasioned from the eggs containing, +when they are in the ovaries, another matter, and that is the glandular +liquor he remarked in the molecules. + +Four days after copulation he opened another, and found in one of the +ovaries four, and in the other three follicules, emptied of their eggs; +and in the horns corresponding to these he found an equal number of +eggs. These eggs were larger than the first that he found three days +after copulation, and were about the size of a small bird-shot; he also +remarked that the internal membrane in these eggs was separated from +the external, and appeared like a second egg in the first. In another, +dissected five days after copulation, he found five empty follicules +in the ovaries, and as many eggs in the matrix, to which they adhered. +These eggs were about the size of duck-shot, and the internal membrane +was more apparent than in the one he had observed before. In one which +he opened six days after copulation there were six empty follicules +in one ovaria, and only five eggs in the corresponding horn, and they +appeared in one mass; in the other ovaria were four empty follicules +and but one egg; these eggs were as big as swan-shot. He opened another +on the seventh day after copulation, and found seven empty follicules; +he also perceived several internal tumours in the matrix, from whence +he took eggs the size of a pistol-bullet. Its membrane was more +distinct than before, but contained only a very clear liquor. In one, +eight days after copulation, he found in the matrix tumours, or cells, +which contained the eggs, but they were very adherent, for he could not +loosen them. In another, nine days after copulation, the cells, which +contained the eggs, were greatly increased, and he saw that the liquor +inclosed by the internal membrane had now got a light cloud floating +upon it. He opened another ten days after copulation and the cloud was +thicker, and formed an oblong body, like a little worm. At last, on the +twelfth day after copulation, the figure of the embryo was distinctly +to be perceived, which two days before only presented the figure of an +oblong body; it was even so apparent that the different members might +be distinguished. In the region of the breast he perceived two red and +two white specks, and in the abdomen a mucilaginous substance, somewhat +reddish. Fourteen days after copulation the head of the embryo was +become large and transparent, the eyes prominent, the mouth open, the +rudiments of the ears appeared; the back-bone, of a whitish colour, +was bent towards the breast, and small blood-vessels came from each +side, whose ramifications ran along the back as far as the feet; the +two red specks, being considerably increased, appeared to be no other +than the ventricles of the heart; by the sides of these red specks +were two white ones, which were the rudiments of the lungs. In the +abdomen the outlines of the liver were seen of a reddish colour, and a +little intricate mass, like a ravelled thread, which was the stomach +and intestines. After this the process was no more than a growth and +expansion of every part till the thirty-first day, when the female +rabbit brings forth her young. + +From these experiments De Graaf concludes, that all viviparous +females have eggs; that these eggs are contained in the testicles, +called ovaries; that they cannot disengage themselves till they are +impregnated, because, he says, the glandular substance, by means of +which the eggs quit their follicules, is not produced till after an +impregnation. He also insists, that those who suppose they have seen +eggs in only two or three days increased in size, must have been +mistaken, for these eggs remain a longer time in the ovary, although +fecundated, and instead of immediately increasing, they rather diminish +until they are descended from the ovaries into the matrix. + +By comparing these observations with those of Harvey, we shall easily +perceive that the principal circumstances have escaped the latter; +and although there are many errors in the reasoning and experiments +of De Graaf, nevertheless this anatomist, as well as Malpighius, has +made better observations than Harvey. They agree in the principal +points, and are both contrary to Harvey; the latter had never seen +the alterations which happen to the ovary; he did not see the small +globules in the matrix which contain the apparatus of generation, and +which De Graaf calls _eggs_. He had not even a supposition that the +foetus existed in this egg; and though his experiments gave us nearly +an exact account of what occurs during the growth of the foetus, +they give us no information either of the moment of fecundation or of +the first development. Schrader, a Dutch physician, who held Harvey +in great veneration, owns that we must not put too great a reliance +in that anatomist in many things, and especially on what he says of +the fecundative moment, for the chicken in fact is in the egg before +incubation, and that Joseph de Aromatarius was the first who observed +it.[J] Although Harvey pretended that every animal proceeds from an +egg, he did not imagine that the testicles of females contained these +eggs, and has only repeated what Aristotle has said on this subject. +The first who speaks of having discovered eggs in female ovaries is +Steno, who says, in dissecting a female sea-dog he saw eggs in the +testicles, although that animal is viviparous; and he adds, that the +testicles of women are analogous to the ovaries of oviparous animals, +whether the eggs fall in any manner into the matrix, or whether there +only falls the matter they contain. Although Steno is the first who +discovered these pretended eggs, De Graaf claims the merit to himself, +and Swammerdam has disputed it with him, insisting that Van Horn had +perceived these eggs before De Graaf. It is true this last writer +stands charged with asserting many things experience has found to be +false. He pretended that a judgment might be formed of the number of +foetuses contained in the matrix by the number of cicatrices, or +empty follicules, in the ovary, which is not true, as we may see by the +observations of Verrheyen,[K] and by those of M. Mery,[L] and by some +of De Graaf's own observations, where he found fewer eggs in the matrix +than cicatrices in the ovaries. Besides, we shall make it appear that +what he says concerning the separation of the eggs, and the manner in +which they descend into the matrix, is not exact; that no eggs exist in +the female testicles; that what is seen in the matrix is not an egg; +and that nothing can be worse founded than the systems endeavoured to +be established on the observations of this famous anatomist. + +[J] See Observ. Justi Schraderi, Amst. 1674. + +[K] Vol. I. chap. iii. Brussels edit. 1710. + +[L] Hist. of the Academ. 1704. + +This pretended discovery of eggs in the testicles of females attracted +the attention of most anatomists; they, however, only met with small +bladders in the testicles of female viviparous animals, these they did +not hesitate to look on as real eggs: they therefore gave the name +of _ovaries_ to the testicles, and called the vesicles eggs, They +also said, with De Graaf, that there are eggs of different sizes in +the ovarium; that the largest in the ovarium of women was not above +the size of a small pea; that they were very small in the young, +but increased with age and intercourse with men; that twenty might +be counted in each ovarium; that these eggs are fecundated in the +ovarium by the spirited part of the seminal liquor of the male; that +afterwards they loosen and fall into the matrix, where the foetus is +formed, from the internal substance of the egg and the placenta of the +external matter; that the glandular substance, which does not exist +in the ovarium till after a fruitful copulation, serves to compress +the egg, and make it quit the ovarium, &c. But Malpighius having +examined things more minutely, detected many of their errors before +they were even received; yet most physicians adopted the sentiments +of De Graaf, without any attention to the observations of Malpighius; +which, notwithstanding, are very important, and to which his scholar +Valisnieri has given a great deal of weight. + +Malpighius and Valisnieri, of all naturalists, speak with the greatest +foundation on the subject of generation. We shall therefore give an +account of their experiments and remarks, to which we cannot pay too +much attention. + +Malpighius having examined a great number of the testicles of cows +and other female animals, affirms that he found vesicles of different +sizes in the testicles of all of them, whether young or adults; these +vesicles are inclosed by a thick membrane, in the inner parts of which +there are blood-vessels, filled with a kind of lymph, or liquor, which +hardens by the heat of the fire like the white of an egg. + +In time a firm yellow body grows which adheres to the testicles. It +is prominent and increases to the size of a cherry, occupying the +greatest part of the ovarium. The body is composed of many little +angular tubes, and its position is irregular; it is covered with a +coat, or membrane, spread over with nerves and blood-vessels. The +appearance and form of this yellow body are not always the same, but +vary according to time. When not above the size of a millet seed, +it is nearly globular, and if divided appears composed of a kind of +variegated net-work. Very often an external covering is observed, +composed of the same substance as the yellow body, around the vesicles +of the ovarium. + +When the yellow body is become nearly of the size of a pea, it is the +shape of a pear, in which is a small cavity filled with liquor; as is +also the case when grown to the size of a cherry. In some of these +yellow substances, when increased to their full maturity, Malpighius +says, a small egg, with its appendages, not bigger than a millet +seed, may be seen near the centre; when they have cast out their eggs +they are empty, resemble a cavernous passage, and the cavities which +inclose them are about the size of peas. He thinks this yellow and +glandular substance nature produces to preserve the egg, and assist +it in leaving the testicles, and perhaps to contribute towards the +generation of the egg itself; consequently, he says, the vesicles, +which are always observed in the ovary, and which are of different +sizes, are not real eggs that may be fecundated, but only serve for the +production of the yellow body where the egg is to be formed. On the +whole, although these yellow substances are not found at all times in +all testicles, we nevertheless always find the first traces of them, +and Malpighius having seen the marks of them in young heifers, cows +that were with calf, and in pregnant women, he reasonably concludes +that this yellow and glandular substance is not, as De Graaf has +supposed, the effect of fecundation, but what produces the infecund +eggs, which leave the ovary without any communication with the male, as +well as to those which leave it after communication. When the latter +falls into the tubes of the matrix, all the rest is performed as De +Graaf has described. + +These observations of Malpighius shew that the testicles of females +are not real ovaries, as most anatomists believe; that the vesicles +they contain are not eggs; that these vesicles never fall into the +matrix; and that the testicles, like those of the male, are kinds +of reservoirs, containing a liquor which must be looked upon as an +imperfect seed of the female, that is perfected in the yellow glandular +body which fills the internal cavity, and is shed when the glandular +substance has acquired its full maturity. But before we decide on this +important point, we must relate the observations of Valisnieri; and we +shall perceive that, though Malpighius and Valisnieri have made good +observations, they have not carried them far enough, nor drawn those +consequences from them which their observations might naturally have +produced, because they were both prejudiced for the system of eggs, and +of the foetus pre-existing therein. + +Valisnieri began his experiments in 1692, on the testicles of a sow, +whose testicles are not composed like those of a cow, sheep, mare, +bitch, female ass, she goat, nor most other viviparous females, for +they resemble a small bunch of grapes, whose seeds are round and +prominent outwardly. Between these seeds there are smaller, which have +not arrived to maturity. These seeds do not appear to be surrounded +with one common membrane; they are, he says, similar to those yellow +substances which Malpighius observed in cows; they are round, of a +reddish colour, their surface sprinkled over with sanguinary vessels +like the eggs of viviparous animals, and together form a mass larger +than the ovary; we may, with a little address, and by dividing the +membrane, separate these grains one by one, and draw them from the +ovary, where they each leave an impression. + +These glandular substances are not of the same colour in every sow, in +some they are red, in others more clear; and they are of all sizes, +from the most minute point to that of a grape. On opening them we find +a triangular cavity filled with a limpid liquor, which coagulates +by the fire, and becomes white like that contained in the vesicles. +Valisnieri hoped to meet with the egg in one of those cavities, but +although he sought for it with the utmost assiduity in the glandular +substance of the ovaries of four different sows, and afterwards in +those of other animals, yet he could never discover the egg which +Malpighius asserts to have met with once or twice. + +Below these glandular substances the vesicles of the ovary were +seen, and which were in a greater or lesser number as the glandular +substances are thicker or smaller, for in proportion as the glandular +substances increase, the vesicles diminish. Some of these vesicles were +the size of a lentil, and others as small as a millet-seed. In crude +testicles twenty, thirty, or thirty-five vesicles might be counted, +but when boiled a greater number are seen; and they are so strongly +connected by fibres and membraneous vessels, that it is impossible to +separate them without a rupture. + +Having examined the testicles of a sow which never had littered, he +found there, as in the rest, glandular bodies, and their triangular +cavities filled with lymph, but never met with the egg either in the +one or the other. The vesicles of this sow which had never littered +were greater in number than in those which had littered or conceived. +In the testicles of another sow which had conceived, and whose young +were much expanded, he found two large glandular substances, that +were empty, and others smaller, in their common state. Having also +dissected many others when with young, he found that the number of +glandular substances was always greater than that of the foetus, +which confirms our observations on De Graaf's experiments, and proves +they are not exact; what he terms the follicules of the ovary being +only the glandular substances, whose number always exceed that of the +foetus. In the ovaries of a sow but a few months old, the testicles +were large, and sprinkled with vesicles pretty well tumefied: between +these vesicles there were four rising glandular substances in one of +the testicles, and more in the other. + +After having finished his experiments on sows, Valisnieri repeated +those of Malpighius on the testicles of cows, and found that all he had +said was conformable to truth; only Valisnieri owns that he has never +been able to find the egg which Malpighius thought he had seen once or +twice in the internal cavity of glandular bodies. Valisnieri proceeded +in his experiments upon a variety of other animals to discover this +egg, but in vain; nevertheless his prejudice for that system induced +him, contrary to his experience, to admit the existence of eggs, which +neither he nor any other man ever did or ever will see. It is scarcely +possible to make a greater number of experiments, or better than he has +done. He observes, as something particular to a ewe, that there are +never more glandular substances in the testicles than foetuses in +the matrix. In young ewes, which have never been with the male, there +is but one glandular substance in each testicle, which when worn away, +another is found; and if a ewe has only one foetus in her matrix, +there is but one glandular substance in the testicles; if there are +two foetuses there will be two glandular substances. This substance +occupies the greatest part of the testicles; after it disappears +another is formed for the purpose of another generation. + +In the testicles of a she-ass he perceived vesicles the size of small +cherries, which evidently prove they are not eggs, since, being of that +size, they could not enter into the horns of the matrix, which are too +narrow in this animal for their reception. + +The testicles of a female dog, wolf, or fox, have a kind of cowl, or +covering, which is produced by the expansion of the membrane that +surrounds the horns of the matrix. In a bitch, whose heat was just +began, and had not been brought to a dog, Valisnieri found this cowl, +which is not adherent to the testicle, internally bathed with a +liquor like whey: he discovered also two glandular substances in the +right testicle, which run almost its whole length. These glandular +substances had each a small nipple, with a little orifice, from which +of itself issued a clear liquor like whey, and when pressed, a greater +quantity came out, which made him imagine, that this liquor was the +same as that found within the cowl: he blew into this orifice, by the +means of a small pipe, and immediately the glandular body was puffed +up; and having introduced a bristle, he easily penetrated to the end of +it: he opened this glandular substance the same way as the bristle was +entered, and found within a cavity which communicated with the orifice, +and which also contained a good deal of liquor. Valisnieri was also +in hopes to discover the egg, but, notwithstanding all his endeavours +and strict attention, he never could perceive it. He remarked, that +the extremity of these nipples, from which this liquor flowed, was +contracted by a sphincter, which served to shut up, or open the orifice +of the nipple: he found also in the left testicle two glandular bodies +with the like cavities, nipples, orifices, and liquor distilling from +them. Still not being able to find the egg, neither in this liquor, +nor in the cavity which contained it, he boiled two of these glandular +substances, hoping that by this means he might discover the object he +was in pursuit of, but it was all in vain. + +Having opened another bitch, eight or nine days after she had been with +the male, he found no difference in the testicles; there were three +glandular substances like the preceding ones, and, like them, distilled +a liquor from the nipples. Here he also persevered in his fruitless +researches after the egg. By the help of a microscope, he perceived the +glandular substances were a kind of vascular net-work, formed by an +infinite number of small globular vesicles which served to filtre the +liquor that issues through the end of the nipple. + +After this he opened another bitch whose heat was off, and having +introduced air between the testicle and its covering, he found it +dilated like a bladder by means of inflation; having raised this cowl, +he found three glandular substances on the testicle, but they had no +apparent nipple, nor orifice, nor did any liquor distil from them. + +In another bitch that had pupped two months, and had five puppies, he +found five glandular substances, which were become very small, and +began to obliterate, without leaving any cicatrices: there still +remained a small cavity in the middle, but it was dry and empty. + +Not content with these, and many more experiments, Valisnieri, who +would not give up his researches after the pretended egg, called +together the most expert anatomists of his country, among whom was M. +Morgagni, and having opened a young bitch at the time of her first +heat, and had been with a male three days before, they examined +the vesicles of the testicles, the glandular substances with their +nipples, orifice, and liquor which flowed from them, and in their +internal cavities, but not an egg was to be found. After this he made +experiments on female goats, foxes, cats, and a great number of mice, +&c. He always found vesicles in the testicles of all those animals, +and often the glandular substances, and the liquor they contained, but +never any egg. + +At length, desirous of examining the testicles of a woman, he had an +opportunity of opening a farmer's wife, a young woman that was killed +by a fall from a tree. She had been married several years, but although +of a good habit of body, yet she had never borne a child. He sought if +the cause of her sterility was not discoverable in the testicles; and +he found the vesicles all replete with a blackish and corrupted matter. + +In the testicles of a girl of eighteen, who had been brought up in a +convent, and, according to all appearances, was a virgin, he found +the right testicle somewhat larger than the left: its shape was oval, +and its surface a little unequal. This inequality was produced by the +protuberance of five or six vesicles of this testicle which advanced +forwards; one of which was more prominent than any of the rest. Having +opened this vesicle, a spirit of lymph issued out: around it there +was a glandular substance in form of a crescent of a yellowish colour +rather bordering on the red. He cut the remainder part of the testicle +transversely, and found many vesicles filled with a limpid liquor, and +remarked that the corresponding trunk to this testicle was very red and +a little longer than the other, as he had frequently observed in female +animals, when in their amorous season. + +The left testicle was as round as the right, it was whiter, and its +surface more smooth; for although there were some vesicles a little +prominent, yet there were not any in form of a nipple; they were all +alike, without any glandular substance, and the corresponding trunk +was neither inflamed nor red. + +In a little girl of five years old, he found the testicles with the +vesicles, blood vessels, fibres and nerves complete. + +In the testicles of a woman sixty years of age, he found some vesicles, +and the vestiges of a glandular substance, which were as so many thick +points of matter of a dark brownish colour. + +From all these observations Valisnieri concludes, that the business +of generation is carried on in the female testicles, which he looked +upon as ovaries, although he never found any eggs in them, but on the +contrary, evidently saw that the vesicles were not eggs. He also says, +that it is not necessary for the seed of the male to enter into the +matrix to impregnate the egg: he supposes that the egg comes from the +nipple of the glandular substance, after impregnation in the ovarium; +that from thence it falls into the trunk, and descends by degrees, till +at last it fastens to the matrix. He adds, he is persuaded that the +egg is concealed in the glandular substance, and that all the business +of generation is performed in the cavity, although neither he nor any +other anatomist, have ever seen or been able to find it. + +According to Valisnieri the spirit of the male seed ascends to the +ovarium, forces its way into the egg, and gives motion to the foetus +that pre-exists therein. In the ovarium of the first woman were eggs, +which not only inclosed in miniature every child she brought forth, +but of the whole human race. That if we cannot conceive this infinite +chain of individuals contained in one, it is the fault of our minds, +the weakness of which is every day perceptible; but it is, upon that +account, no less true, that every animal which has been, is, and will +be, were created all at one time, and inclosed in the first females. +The resemblance of children to parents only proceeds, continues he, +from the imagination of the mother, the power of which is so great on +the foetus that it can produce on it spots, marks, disproportions, +and extraordinary births, as well as perfect resemblances. + +This system of the eggs, which is unreasonable, and without foundation, +would, nevertheless, have obtained the unanimous suffrages of all +physicians, if, when it was first endeavoured to be established, +another system had not been formed on the discovery of spermatic +animals. + +This discovery, for which we are indebted to Leeuwenhoeck and +Hartsoeker, has been confirmed by Andri, Valisnieri, Bourguet, and +many other observers of Nature. I shall relate what has been said +concerning the spermatic animals which are found in the seminal liquor +of all males: they are in such vast numbers that the semen seems to be +entirely composed of them; and Leeuwenhoeck pretends to have seen many +millions of them in a drop smaller than the smallest grain of sand. +Although we do not meet with any in female animals they abound in all +males, both in the semen emitted naturally and that in the testicles, +as well as in the seminal vesicles. If the semen of a man is exposed +to a moderate heat it thickens, and the motions of all the animalcules +immediately cease, but if allowed to cool it becomes thinner, and the +animals preserve their motion till the liquor thickens as it dries +away. The thinner the liquor becomes the more the animalcule increase, +and if water is added it will appear like a substance of small animals. +When the motion of these animalcule is nearly finished, whether from +heat, or any other cause, they seem to assemble closer together, and +have a whirling motion in the centre of a small drop which may have +been taken out for observation, and appear all to perish at one and the +same time, whereas in the larger portion of the liquor they are easily +seen to perish successively. + +The animalculę, say they, have different figures in different animals; +nevertheless they are all long, slender, without any appearance of +limbs, and move with rapidity. The fluid which contains them, as we +have already observed, is heavier than blood. The semen of a bull +afforded Verrheyen, by a chemical process, first phlegm, afterwards a +considerable quantity of foetid oil, but little volatile salt, and +much more earth than he could have thought.[M] This author appears +surprised that in rectifying the distilled liquor he could not draw any +spirit from it, and being persuaded it contained a great quantity, he +attributed the evaporation to its great subtility: but may it not be +more reasonably imagined that it contains very little or no spirits, +as neither its consistency nor smell announce any ardent spirit, and +which is only plentifully found in fermented liquors? besides, with +respect to volatile spirits, the horns, bones, and other solid parts +of animals, afford more than all the liquor of the animal body. What +anatomists have called animal spirits, _aura seminalis_, may possibly +not exist; and it is certainly not these spirits which agitate the +particles seen moving in the seminal liquors; but we will here relate +the principal observations that have been made on this subject. + +[M] See Veerheyen, sup. anat. tom. ii. page 69. + +Leeuwenhoeck observed, in the semen of a cock, animals which resemble +the figure of an eel, but so exceedingly minute, that he pretends fifty +thousand would not equal in size a grain of sand; and in that of a +rat many millions would be required to make the thickness of a hair, +&c. This observer imagined that the whole substance of the semen was +only a mass of these animalcules. He perceived these animalculę in +the semen of men, quadrupeds, birds, fishes, insects, &c. In that of +grasshoppers they were long and slender. They are attached, he says, by +their extremities, and the inferior of which he calls the tail, had a +quick motion, like that of the tail of a serpent, when the upper part +is motionless. He further adds, that in the semen of young animals the +animalculę are motionless, but as the age for reproduction comes on +they move about with great vivacity. + +In the semen of a male frog he observed animalculę, at first they +were imperfect and motionless, but some time afterwards he found them +living: they were so very small, he says, that ten thousand would +scarcely equal the size of a single egg of the female. It was only +those in the seminal liquor of the frog which had life and motion. + +In the semen of a man, and that of a dog, he pretends to have seen two +kinds, which he looked upon as males and females. Having inclosed the +seed of a dog in a vial, he says, that numbers of the animalculę died +the first day; the second and third there died still more, and very +few remained alive the fourth. But having repeated this experiment +on the semen of the same dog, he found, at the end of seven days, +live animalculę, some of which swam with as much swiftness as in +fresh-extracted semen; and having opened a bitch which had been three +times with the same dog, he could not perceive by the naked eye any +seminal liquor of the male in either of the horns of the matrix; but +by help of a microscope he discovered the spermatic animals of the +dog in both horns of the matrix, and great numbers of them in that +part of the matrix adjoining to the vagina, which, says he, evidently +proves that the male semen enters the matrix, or at least that the +spermatic animals of the dog had got there by their own motion, which +is sufficient to carry them four or five inches in half an hour. In the +matrix of a doe rabbit, which had just received the buck, he likewise +observed an infinite number of spermatic animals; he says, that their +bodies are round, with long tails, and that they often change their +forms, especially when the humid matter in which they swim evaporates +and dries. + +Leeuwenhoeck's experiments have been frequently repeated and found +conformable to truth. There have been some inclined to exceed him in +these discoveries. Dr. Dalenpatius having observed the seminal liquor +of a man, not only pretended to have discovered animals like tadpoles, +whose bodies appeared nearly the size of a grain of wheat, and their +tails four or five times longer than their bodies, and which moved +with great agility, but, what is still more marvellous, he observed +one of these animals quit its covering; upon which it was no longer an +animalcule, but had become a human body, the two legs of which, he +affirms, were very discernible, as were the arms, breast, and head.[N] +But by the figures which this author has given of this pretended +embryo, it is evident his assertion is false. He might suppose he +saw what he relates, but he was mistaken; for the embryo, such as he +describes, was more formed on quitting this covering, and the state +of a spermatic worm, than it would have been at the end of a month or +five weeks in the matrix of its mother; therefore this observation of +Dalenpatius, instead of having been confirmed by other observations, +has been rejected by every naturalist, the most exact and accurate of +which have only discovered, in the seminal liquor of man, round and +oblong bodies, which seemed to have long tails, but without any kind of +members. + +[N] See Nouvelles de la Republique des Lettres, Ann. 1699, page 552. + +It might be said that Plato had spoken of these spermatic animals +which become human forms; for he says, "Vulva quoque matrix que in +foeminis eadem ratione animal avidem generandi, quando procul a +foetu per ętatis florem, aut ultra diutius detinetur, ęgre fert +moram ac plurimum indignatur, passimque per corpus oberrans, meatus +spiritus intercludit, respirare non finit, extremis vexat angustiis, +morbis denique omnibus premit, quosque atrorumque Cupido amorque quasi +ex arboribus foetum fructumve producunt, ipsum deinde decerpunt, & +in matricem velut agrem inspargunt; hinc animalia primum talia, ut nec +propter parvitatem videantur, necdum appareant formata, concipiunt: mox +quę conflaverant, explicant, ingentia, intus enutriunt, demum educunt +in lucem, animaliumque generationem perficiunt." Hippocrates, in his +treatise _De Dięta_, seems also to insinuate, that the seed of animals +is replete with animalcules. Democritus speaks of certain worms which +take the human figure, and Aristotle says, that the first men came out +of the earth in the form of worms; but neither the authority of Plato, +Hippocrates, Democritus, Aristotle, nor the observation of Dalenpatius, +can make us receive the idea that these spermatic worms are small human +bodies, concealed under a covering; for it is evidently contrary to +experience and observation. + +Valisnieri and Bourguet, whom we have quoted, discovered small worms +in the seed of a rabbit, one of whose extremities was thicker than +the other; they were very lively and active, struck the liquor with +their tails, and twisted and turned themselves like snakes. At last +(says Valisnieri) I clearly perceived them to be real animals, "e gli +riconobbi, e gli giudicai senza dubitamento alcuno per veri, verissimi +arciverissimi vermi[O]." This author, who was prejudiced with the +system of eggs, has, nevertheless, admitted of spermatic worms, and +taken them for real animals. + +[O] Opere dell. Cav. Valisnieri, vol. II. page 105. + +M. Andry having made observations on these spermatic worms of a man, +pretends that they are only found in the age proper for generation; +that in the younger years, and in old age, they do not exist: that in +those affected with venereal disorders there are very few, and those +are languishing, and for the most part dead: that in impotent persons +we do not see any alive; that these worms in the semen of men have +larger heads than in that of other animals, which agrees, he says, with +the figure of the foetus and the child; and he adds, those people who +too frequently enjoy female amours, have generally but few or none of +these animalcules in their semen. + +Leeuwenhoeck, Andry, and many others, strenuously opposed the +egg system; they had discovered in the semen of all males living +animalcules; they proved that these animalcules could not be regarded +merely as dwelling in this liquor, since their bulk was greater than +that of the liquor itself; and that nothing like them was found +either in the blood, or in the other animal liquors. They asserted, +that females furnished nothing similar, nothing alive; and it was +therefore evident that the fecundity attributed to them belonged, +on the contrary, to males alone: and that the discovery of these +spermatic animals in the semen tended more to the explanation of +generation than all that had been before supposed; since, in fact, +what was most difficult to conceive in generation, was the production +of the living part, all the rest being only accessary operations, +and therefore no doubt could remain but these little animals were +destined to become men, or perfect animals of their kind. When it was +opposed to the partizans of this system, that it did not seem natural +to suppose that so many millions of animalcules, every one of which +might become a human being, should be employed for a purpose of which +one alone was to reap the advantage; when it was asked them, why this +useless profusion of the shoots of human beings? they answered, that +it was only consonant with the common munificence of nature: that +out of many millions of seeds which plants and trees produce, but a +very few succeed, and therefore we must not be surprised at the same +circumstance in spermatic animals. When the infinite minuteness of the +spermatic worm, compared to man, was objected to them, they answered, +by the example of the seed of trees; and they added, with some +foundation, metaphysical reasonings, by which they proved that great +and small being only relations, the transition from small to great, or +from great to small, was executed by nature with still more facility +than we can conceive. + +Besides, continue they, have we not very frequent examples of +transformation in insects? do we not see small aquatic worms become +winged animals, by only throwing off their coats, which were their +apparent and external forms? and may not spermatic animals, by a +similar transformation, become perfect animals? All therefore, they +conclude, concurs to favour this system of generation, and confuting +that founded on eggs; and if there are eggs in viviparous females, +the same as in the oviparous, these eggs will only be the necessary +matter for the growth of the spermatic worm, which enters into the +egg by the pedicle that adheres to the ovarium, and where it meets +with food ready prepared for it. All the worms which find not this +passage through the pedicle into the egg will perish, and that one +which alone has traced its way will arrive at its transformation. The +difficulty of meeting with the passage in the pedicle of the egg, can +only be compensated by the infinite number of spermatic worms. It is a +million to one that any particular spermatic worm will meet with the +pedicle of the egg, and therefore what at first appears a profusion is +highly necessary. When one has entered, no other can introduce itself, +because, say they, the first worm entirely shuts up the passage, or +there is a valve at the entrance of the pedicle, which is free when +the egg is not absolutely full; but when the worm has filled the egg, +the valve can no longer open although impelled by another worm. This +valve is very well imagined, because, if the first worm should chance +to return, it opposes its egress, and obliges it to remain and undergo +the transformation. The spermatic worm then becomes the foetus, the +substance of the egg its food, the membranes, its covering, and when +the nutriment in the egg is nearly exhausted, the foetus adheres to +the internal skin of the matrix, and thus derives nourishment from the +parent's blood, till by its weight, and augmentation of its strength, +it breaks through its imprisonment, and comes perfect into the world. + +By this system it was not the first woman who inclosed all mankind, but +the first man who contained all posterity in his body. The pre-existing +germs are no longer embryos without light, inclosed in the eggs, and +contained one in another, ad infinitum; but they are small animals, the +little homunculę organized and actually living, included in each other +in endless succession, and to which nothing is wanting for them to +become perfect animals, and human beings, but expansion, assisted by a +transformation similar to that which winged insects undergo. + +As our present physicians are divided on these two systems of spermatic +worms and eggs, and as all those who have lately written on generation +have adopted one or the other of these opinions, it seems necessary to +examine them with care, and to shew that they are not only sufficient +to explain the phenomena of generation, but are also founded on +suppositions void of all probability. + +Both suppose an infinite progression; which, as we have said, is not so +much a reasonable supposition as an illusion of the mind. A spermatic +worm is more than a thousand million times smaller than a man; if, +therefore, we suppose the body of a man as an unit, the size of the +spermatic worm can only be expressed by the fraction 1/1000000000; and +as man is with respect to the spermatic worm of the first generation, +what this worm is to that of the second generation, the size of the +last spermatic worm cannot be expressed but by a number composed of +nineteen cyphers; and so likewise the size of the spermatic worm of the +third generation will require 28 cyphers; that of the fourth generation +37; the fifth 46, and the sixth 55 cyphers. To form an idea of the +minuteness represented by this fraction, let us take the dimensions +of the sphere of the universe from Sol to Saturn, and supposing the +sun a million times larger than the earth, and about a thousand +solar diameters distant from Saturn, we shall perceive that only 45 +cyphers are required to express the number of cubic lines contained +in this sphere; and, by reducing each cubic line into a thousand +millions of atoms, 54 cyphers are only required to express that +number; consequently a human being will be greater, with relation to a +spermatic worm of the sixth generation, than the sphere of the universe +is with relation to the smallest atom which is possible to be perceived +by the assistance of a microscope. What would it be if we were to carry +it to ten generations? The minuteness would be so great as to leave us +no mode of expressing it. The probability of this opinion, therefore, +evidently disappears in proportion as the object diminishes. This +calculation may be applied to eggs as well as spermatic worms, and the +want of probability is general to both; it will, no doubt, be said, +that matter being divisible, _ad infinitum_, there is no impossibility +in this diminution of size; and although it is not probable, yet we +must regard this division of matter as possible, since we can always, +by thought, divide an atom into a number of parts. But I answer, that +the same illusion is made use of on this infinite divisibility as +on every other geometrical and arithmetical infinity; they are only +abstractions of the mind, and have no existence in nature. If we look +on infinite divisibility of matter as an absolute infinity, it is easy +to demonstrate that in that sense it does not exist; for, if once we +suppose the smallest atom possible, by that supposition this atom will +necessarily be indivisible, since if it were divisible it would no +longer be the smallest atom possible, which would be contrary to the +supposition. It therefore seems to me, that every hypothesis where a +progress, _ad infinitum_, is admitted, ought to be rejected not only as +false, but as void of all probability; and as the system of eggs and +spermatic worms supposes this progress, they should not be admitted in +philosophy. + +Another great difficulty against these two systems is, that in the egg +system the first woman contained the male and female eggs: the male +eggs contained only a generation of males; and that, on the contrary, +the female eggs contained thousands of generations, both of males and +females; insomuch that, at the same time, and in the same woman, there +was always a certain number of eggs capable of developing themselves to +infinity, and another number which would be unfolded but once. The same +circumstance must occur in the other system, and therefore I ask if +there is the smallest appearance of probability in these suppositions? + +A third difficulty arises against these two systems, which is, the +resemblance that children bear, sometimes to the father and sometimes +to the mother, and sometimes to both; and the evident marks of +extraordinary difference in mules, &c. If from the spermatic worm of +the father the foetus is produced, how can the child resemble the +mother; and if the foetus is pre-existing in the egg of the mother, +how can the child resemble its father? or if the spermatic worm of a +horse, or the egg of a she-ass contains the foetus, how can the mule +participate in the nature and figure of both the horse and the ass? + +These general difficulties, which are invincible, are not the only +ones that can be made against these systems; there are particular ones +which are no less potent. To begin with the system of spermatic worms, +may it not be asked of those who admit of it, how they think this +transformation is made? and object to them, that insects have not, nor +cannot have any relation with what they suppose. For the worm which is +to become a fly, or the caterpillar which is to become a butterfly, +passes through a middle state, and when it ceases to be a chrysalis, +it is completely formed and has acquired its full size, and is then in +a condition of engendering; whereas in the pretended transformation +of the spermatic worm into man, it cannot be said to be in a state of +chrysalis, and even if we should suppose one during the first days of +conception, why does not the production of this chrysalis, instead of +an unformed embryo, suppose an adult and perfect being? We plainly see +how analogy is here violated; and that far from confirming this idea of +the transformation of the spermatic worm, it is instantly destroyed by +examination. + +Besides, the worm which is transformed into a fly proceeds from an egg; +the egg is the produce of the copulation of the male and female, and +includes the foetus, which must afterwards enter into a chrysalis, +before it arrives at its state of perfection, as a fly; in which form +alone it has an engendering power; whereas the spermatic worm has no +faculty of generation, nor proceeds from an egg. Even should we allow +the semen to contain eggs, from whence issue spermatic worms, the same +difficulty will still remain, for these supposed eggs have not the +copulation of the two sexes for their principle of existence, as in +insects; consequently the partizans of that opinion cannot pretend +any similarity, nor derive any advantage from the transformation of +insects; which rather destroys the basis of their explanation. + +When the innumerable multitude of spermatic worms are opposed to those +physicians who are prejudiced by this system, they answer, as before +observed, by the examples of plants and trees. But this comparison +is not entirely just, because all the spermatic worms excepting one +perish by absolute necessity, which is not the case with the seeds of +a tree or plant, for those which do not become vegetables, serve as +food for other organized bodies, and for the expansion and reproduction +of animals; whereas we do not see any use for the spermatic worms, or +any end to which we can refer their prodigious superfluity. On the +whole, I only make this remark in reply to what is, or may be said on +this matter; for I own, that no arguments drawn from final causes will +either establish or destroy a physical system. + +Another objection made against this opinion is, there being, to all +appearance, an equal number of separate worms in the seed of all kinds +of animals, for, say they, it is natural to imagine, that in those +kinds where foetuses are most abundant, as in fishes, insects, &c. +the number of spermatic worms should be more numerous than in those +where generation is least abundant, as in man, quadrupeds, birds, &c. +for if they are the immediate cause of production, why is there no +proportion between their number and that of the foetus? Besides, +there is no proportionable difference in the size of most kinds of +spermatic worms, those of large animals being as small as those of the +least. Those of a rat, and those of a man, are nearly the same, and +when there is any difference it is no ways relative to the size of +the individual. The Calmar, which is a very small fish, has spermatic +worms above one hundred thousand times larger than those of a man or a +dog. Another proof these worms are not the immediate and only cause of +generation. + +The particular difficulties that may be raised against this egg system +are no less considerable. If the foetus exists in the egg before the +communication of the male with the female, why do we not perceive the +foetus as well in those eggs produced before as after copulation? +We have before recounted the observations of Malpighius, who says +he always found the foetus in those eggs produced by hens that had +received the cock, and only a mass or mole in the cicatrice of those +who had not; it is therefore very clear that the foetus does not +exist in the egg till after impregnation. + +Another difficulty against this system is, that not only the foetus +is not seen in eggs before the junction of the sexes, but even the +existence of eggs in viviparous animals is by no means proved. Those +physicians who pretend that the spermatic worm is the foetus +enveloped in a covering, are at least assured of spermatic worms; but +those who affirm that the foetus is pre-existing in the egg, have no +proof of the existence of the egg itself; on the contrary, there is a +probability, almost equivalent to a certainty, that these eggs do not +exist. + +Although the partizans of the egg system do not agree what must be +looked on as the true egg in the female testicle, nevertheless they all +think that impregnation is made in the testicle called the _ovarium_, +without paying any attention that if it was so most foetuses would be +found in the abdomen instead of the matrix, for the superior extremity +of the trunk being separated from the ovarium, the pretended eggs must +often fall into the abdomen. Now, it is certain that this case is +extremely rare, and, I believe, never happened, unless occasioned by +some accident. + +The general difficulties and objections against these two systems +have been noticed by the author of _Venus Physique_, whose treatise, +although very short, has more philosophical ideas than there are in +many folio volumes on generation. As this book is very public, and +the accuracy with which it is written will not permit any extract, I +shall only observe, this author is the first who has returned into the +road of truth, from which we were farther strayed than ever, since the +supposition of the egg system, and the discovery of spermatic animals. +Nothing therefore remains farther to be said, and I shall conclude with +relating a few particular experiments, some of which have appeared +favourable, and others contrary, to these systems. + +In the History of the Academy of Sciences of Paris, 1701, some +objections are proposed by M. Mery against the egg system. This able +anatomist supports, with reason, that the vesicles found in the female +testicles are not eggs, but are so adherent to the internal substance +of the testicle that they cannot be naturally separated therefrom; +that if they could separate themselves from this substance it would +be impossible for them to get out, because the common membrane, which +surrounds all the testicle, is a web of too firm a texture to admit of +a conception; that a vesicle, or round soft egg, could open a passage +in it; and as the greatest number of physicians and anatomists were +prejudiced in favour of the egg system, and, from the experiments of De +Graaf, believed that the number of cicatrices in the testicles marked +the number of foetuses, M. Mery mentions the testicles of a woman, +where there was such a quantity of these cicatrices, that, agreeable to +this system, would have supposed a fecundity almost beyond imagination. +These difficulties excited other partizans of the egg system to make +new researches. M. Duverney examined and dissected the testicles of +cows and sheep: he pretended that the vesicles were eggs, because there +were some less adherent to the testicles than others, and insisted it +was natural to believe, that when they came to perfect maturity they +were separated altogether, especially as by inflating the internal +cavity of the testicle the air passed between these vesicles and the +adjoining parts. M. Mery only answers that this not a sufficient proof, +since these vesicles have never been seen separate from the testicles. +M. Duverney remarked the glandular bodies on the testicles, but he did +not look on them as an essential and necessary part towards generation, +but merely as accidental exuberances, like gall-nuts, on the oak. +M. Littre, whose prejudice for the egg system was still greater, +pretended, not only that the vesicles were eggs, but even asserted +he had discovered in one of them a well-formed foetus, of which he +distinguished the head and trunk very perfectly, and even gave the +dimensions. But besides this wonder being only seen by that gentleman, +and no other naturalist, it is sufficient to read his Memoire[P] to +perceive how doubtful was the fact. By his own words we find the matrix +was schirrhous, that the testicle was corrupted, and that the vesicle, +or egg, which contained this imaginary foetus was smaller than the +other vesicles, or eggs, which did not contain any thing, &c. + +[P] Anno 1701, page 3. + +A famous experiment, in favour of the egg system, is supplied by De +Nuck; he opened a bitch three days after copulation; he drew out one of +the horns of the matrix, and made a ligature in the middle, so that the +upper part of the passage could have no communication with the lower; +after which he replaced this horn, and closed up the wound, with which +the bitch seemed but little incommoded. At the end of twenty-one days +he opened it again, and found two foetuses in the upper part, that +is between the testicles and the ligature; but in the lower part there +was no foetus. In the other horn of the matrix, which had not been +tied by a ligature, he found three foetuses, which were regularly +disposed, which proves, he says, that the foetus does not proceed +from the seed of the male, but exists in the female egg. Supposing this +experiment, which has only been made once, was always followed with the +same effect, we should not then be right in concluding that fecundation +is made in the ovary, and that eggs are detached therefrom which +contain the foetus completely formed. It would only prove that the +foetus may be formed in the upper parts of the horns of the matrix as +well as in the lower; and it seems very natural to imagine that the +ligature, compressing the middle of the horns of the matrix, impelled +the seminal liquors, which are in the lower parts, to issue out, and +thus destroy the business of generation in them. + +Thus we have gone through the opinions of anatomists and physicians +on the subject of generation; and it now only remains for me to +recount what I have been enabled to draw from my own researches +and experiments, and it will then be seen whether my system is not +infinitely more agreeable to Nature than any of those I have given an +account of. + + + + +CHAPTER VI. + +EXPERIMENTS ON THE METHOD OF GENERATION. + + +I often reflected on the above system, and was every day more and more +convinced that my theory was infinitely the most probable. I then began +to suppose that, by a microscope, I might be able to attain a discovery +of the living organic particles, from which I thought every animal +and vegetable drew their origin. My first supposition was, that the +spermatic animalcules seen in the seed of every male, might possibly be +these organic particles; on which I reasoned as follows: + +If every animal and vegetable contain a quantity of living organic +particles, these particles would be found in their seed, and in a +greater quantity than in any other substance, because the seed is an +extract of what is most analogous to the individual, and the most +organic; and the animalcule we see in the seed of males are, perhaps, +only these same living organic molecules, or at least the first union, +or assemblage of them. But if this is so, the seed of the female must +also contain similar living organic molecules, and, consequently, we +ought to find moving bodies there as well as in the male: and since the +living organic particles are common both to animals and vegetables, +we should also find them in the seeds of plants, in the nectarium, +and in the stamina, which are the most essential parts of vegetables, +and which contain the organic molecules necessary for reproduction. I +then seriously thought of examining the seminal liquors of both sexes, +and the germs of plants, with a microscope. I thought, likewise, that +the reservoirs of the female seed might possibly be the cavities of +the glandular bodies, in which Valisnieri and others had uselessly +sought for the egg; and at length determined to undertake a course of +observations and experiments. I first communicated my ideas to Mr. +Needham, a gentleman well known for his microscopical observations, +and read to him the first part of this work; he seemed to approve of +these ideas, and did me the favour to lend me his microscope which +was infinitely superior to my own. At the same time I communicated my +system and project of experiments to Messrs. Daubenton, Gueneau, and +Dalibard, all of whom encouraged me to persevere in my determination, +and from whom, in the course of making those experiments, I received +much assistance, particularly from Mr. Daubenton. + +Persons not experienced in the use of the microscope will not be +displeased that I here insert some remarks which will be useful to +them, if they repeat the following experiments, or make new ones. +We should give the preference to double microscopes, in which we +see objects perpendicularly, from their having a plain or concave +mirror, which shews the objects clear; the concave mirror is the +most preferable when the observations are made with the strongest +lens. Leeuwenhoek, who undoubtedly has been the greatest and most +indefatigable of all microscopical observators, is said to have +only made use of simple microscopes, with which he viewed objects +horizontally. If this is true, it is necessary to remark, that most of +the plates given by Leeuwenhoek of microscopical objects, especially +spermatic animals, represents them much thicker and longer than he +really saw them, which renders the microscopes we speak of preferable +to the horizontal, as they are more stable; the motion of the hand, +with which the microscope is held, producing a little trembling, which +causes the object to appear wavering, and never presents the same part +for any time. Besides, there is always a motion in the liquors caused +by the agitation of the external air, at least, if we do not put the +liquor between two plates of glass, or even fine talc, which diminishes +somewhat of its transparency, and greatly lengthens the experiment; but +the horizontal microscope, whose tables are vertical, has the still +greater inconvenience, that the most ponderous parts of the drop of +liquor fall to the bottom; consequently there are three motions, that +of the trembling of the hand, the agitation of the fluid by the action +of the air, and also that of the parts of the liquor falling to the +bottom: from the combination of which, certain small globules, which +we see in these liquors, may appear to move by their own motion and +powers, while they only obey the compounded power of those three causes. + +When we put a drop of liquor on the table of the double microscope, +although horizontally placed, and in the most advantageous situation, +we still see one common motion in the liquor, which forces all what it +contains to one side. We must wait till the fluid is in an equilibrium +and at rest, before we make our observations; for it often occurs, +that this motion of the fluid hurries away many globules, and forms +a kind of whirling motion, which returns one of these globules in +a very different direction to the others. The eye is then fixed on +the globules, and seeing one take a different course from the rest, +supposes it an animal, or at least a body, which moves of itself, +whereas its motion is only owing to that of the fluid; and as the +liquor is apt to dry and thicken in the circumference of the drop, +endeavours must be made to fix the lens on the centre of it. The drop +should also be as large as possible, and contain as much liquor as will +permit a sufficient transparency, to see perfectly what it contains. + +Before we begin to make observations, we should have a perfect +knowledge of our microscope. There is no glass whatsoever but in which +there are some spots, bubbles, threads, and other defects, which +should be nicely inspected, in order that such appearances should not +be represented as real and unknown objects: we must also endeavour +to learn what effect the imperceptible dust has which adheres to the +glasses of the microscope; a perfect knowledge of which may be acquired +by observing the microscope several times. + +To make proper observations, the sight, or focus, of the microscope +must not precisely fall on the surface of the liquor, but a little +above it; as not so much reliance should be placed on what passes upon +the surface, as what is seen in the body of the liquor. There are often +bubbles on the surface which have irregular motions produced by the +contact of the air. + +We can see much better with the light of two short candles, than in the +brightest day, provided this light is not agitated, which is avoided by +putting a small shade on the table, inclosing the three sides of the +lights and the microscope. + +It will often appear as though dark and opaque bodies become +transparent, and even take different colours, or form concentrical and +coloured rings, or a kind of rainbow on the surface; and other matters, +which are seen at first sight transparent and clouded, become black and +obscure; these changes are not real, but only depend on the obliquity +the sight falls on the body with, and the height of the plain in which +they are found. + +When there are bodies in a liquor which seem to move with great +swiftness, especially when they are on the surface, they form a +furrowed motion in the liquor, which appears to follow the moving body, +and which we might be inclined to mistake for a tail. This appearance +deceived me at first, but I clearly perceived my error, when these +little bodies met others which stopped them; for there was no longer +any appearance of tails. These are the remarks which occurred during +my experiments, and which I submit to those who would make use of the +microscope for the observation of liquors. + +[Illustration: _PLATE I._] + + +EXPERIMENTS. + +I. I took from the seminal vessels of a man, who died a violent death, +and whose body was still warm, all the liquor therein contained, and +put it into a small bottle; of this I put a drop on the table of the +microscope, without the addition of water or any other liquor. The +first thing which presented, was a vapour which steamed from the liquor +towards the lens, and obscured it. These vapours being dissipated, I +perceived large filaments, (_fig. 1._) which in some places seemed to +extend into different branches, and in others to intermingle together. +These filaments clearly appeared to be internally agitated by an +undulating motion, and looked like hollow tubes which contained some +moving substance. I distinctly saw two of these filaments (_fig. 2._) +were joined together, and had a vibration nearly like that of two +extended strings, which are tied at the two extremities, and pulled +asunder in the middle. These filaments were composed of globules which +touched each other, and resembled beads. I afterwards saw filaments +which swelled in certain parts, and I observed, that on the side so +swelled small globules came out, which had a distinct motion like that +of a pendulum; these small bodies were fastened to the filaments by +a small thread, (_fig. 3._) which lengthened gradually as the little +body moved; and at last I saw these little bodies entirely separated +from the large filament, carrying after them the small thread which +connected them. As this liquor was very thick, and the filaments too +near each other, I dilated another drop with rain water, in which +I was assured there were no animals. I then saw the filaments much +separated, and very distinctly perceived the motion of these little +bodies, which was now more free, and they swam much quicker; and if +I had not seen them separate from the filaments, and carry along +with them their thread, I should have taken the moving body in this +second observation for an animal, and the thread for its tail. I then +attentively observed one of these filaments, that was much thicker than +these small bodies, and I had the satisfaction of seeing two of those +bodies which separated with difficulty, drag along with them a long and +small thread, which obstructed their motion. + +This seminal liquor was at first very thick, but by degrees it became +more fluid; in less than an hour it was almost transparent; and in +proportion as this fluidity increased, the phenomena changed, as I +shall relate. + +II. When the seminal liquor attained more fluidity, the filaments were +no longer to be seen, but the little bodies appeared in great numbers; +they have for the most part a motion like that of a pendulum, and they +draw after them a long thread, which it may clearly be perceived they +want to get rid of; their motion forwards is very slow, vibrating to +the right and left. The motion of a boat fastened in the midst of a +rapid stream to one fixed point, pretty well represents the motion +of these bodies, excepting that the boat remains in the same place, +whereas they advance by degrees; but they do not always keep the +same parts in the same direction; but at each vibration they take a +considerable rolling motion; so that, besides their horizontal motion, +they have one of a vertical balance, which proves that these bodies +are of a globular figure, or, at least, that their lowest part is not +sufficiently extended to maintain them in the same position. + +III. At the end of two or three hours, when the liquor was more fluid, +we saw a greater quantity of these moving bodies. They seemed to be +more free; the threads were shorter; their progressive motion was more +direct, and their horizontal motion was greatly diminished; for the +longer the threads are, the greater is the angle of their vibration; +and in proportion as these threads diminish in length, the vibratory +motion lessens, and the progressive motion increases. The vertical +balance still subsisted, and was always plainly perceptible. + +IV. In five or six hours the liquor attained its utmost fluidity. Most +of these moving substances were entirely disengaged from their threads; +they were of an oval figure, (_fig. 4._) and moved progressively +with great swiftness, and by their various motions had a stronger +resemblance than ever to real animals. Those who had their threads +still adhering, were not so brisk as the others; and among these that +had not threads, some seemed to change their shape and size, some were +round, some oval, and others thicker at their extremities than in the +middle; the balancing and rolling motion was still observable. + +V. At the end of twelve hours a kind of gelatinous matter was settled +at the bottom of the bottle: it was of an ash-colour, and of a +tolerable consistency; the liquor that swam above was almost as clear +as water, with a kind of bluish tint, resembling water in which a +little soap had been dissolved; nevertheless it still preserved its +viscidity. The moving bodies had then a great activity, were loosened +from their threads, and moved in all directions. I saw some of them +change their form, and from oval become round; and others separate, +and from one oval form two. As they became smaller, their activity +increased. + +VI. In twenty-four hours the liquor had deposited a greater quantity of +gelatinous matter. I diluted it with water, but it did not readily mix, +and required a considerable time to dissolve. It then appeared composed +of an infinite number of opaque tubes that formed a kind of net-work, +in which no regular disposition nor the least motion could be seen: +in the clear liquor some few small bodies were still moving. The next +morning there were also a very few; but after that time I saw no more +in this liquor than in the globules, without any appearance of motion. + +These experiments were repeated several times with the most possible +exactness; and I am persuaded that those threads above mentioned are +not tails, nor do they make any part of the individual body; for these +threads have no proportion with the rest of the body; they are of +different sizes, although the moving bodies are always nearly of the +same, at the same time. The globule appears embarrassed in its motion, +as its tail is longer or shorter; sometimes it cannot advance, but move +only from right to left, or from left to right, when the tail is very +long; and it is clearly seen that they use great efforts to get rid of +them. + +VII. Having taken the seminal liquor from another man but just dead, +and still warm, I put a drop of it on the table of the microscope, and +it immediately liquified; it had at first a condensed appearance, and +seemed to form a compact web, composed of long and thick filaments, +which grew from the thickest part of the liquor. These filaments +separated in proportion as the liquor became more fluid, and at +length they divided into globules, which at first seemed not to have +sufficient power to set themselves in motion, but this power increased +as they separated from the filament, from which they made many efforts +to disengage themselves. Each of them in this struggle drew out tails +from the filaments of different sizes, some of which were so thin +and so long as to have no proportion with the bodies, which were all +so much the more embarrassed as these threads or tails increased in +length. The angle of their vibratory motion was also much greater as +those filaments were longer: and their progressive motion so much the +more remarkable as these tails were shorter. + +VIII. Having continued these observations for fourteen hours, I +perceived that these threads, or tails, were continually lessening, and +became so fine, that at last their extremities were no longer visible, +and at length the whole entirely disappeared. At this time the globules +absolutely ceased their horizontal vibrations; their progressive motion +was direct, although they had always the vertical balancing motion, +like the rolling of a ship. When disencumbered of these threads, the +bodies were oval, transparent, and perfectly like those pretended +animals seen in the liquor of an oyster on the seventh day, and still +more to those found in the jelly of roast veal at the end of the fourth +day. + +IX. Between the tenth and eleventh hour the liquor became extremely +fluid, and all the globules appeared to proceed in ranks from one and +the same side; (_fig. 5._) they passed over the table of the microscope +in less than four seconds; they were ranged seven or eight in front, +and moved on successively, as troops march in files. I observed this +singular instance for more than five minutes; and as their course +did not finish, I was desirous of finding the source: and, having +gently moved my glass, I perceived that all these moving globules came +from a kind of mucilage, (_fig. 6._) where the filamentary net-work +continually produced them more abundant and much quicker than the +filaments had ten hours before. There was still a remarkable difference +between these moving bodies produced in the thick liquor, and those +produced when the liquor became more fluid; these last had no thread +behind them, their motion was quicker, and they went in flocks like +sheep. I observed the mucilage from whence they issued for some time, +and perceived it diminished, and was successively converted into +moving globules, till the diminution of more than half the bulk; after +which, the liquor being too dry, this mucilage became obscure in its +middle, and all the environs were divided by the small threads which +appeared to be formed from the bodies of these moving globules which +were destroyed as it dried up, not in one single mass, but in long +threads, regularly disposed, with quadrangular intervals, forming a +net-work, very like to a cobweb, on which the moisture hung in an +infinite number of globules. + +X. I perceived by the first experiment, that these little moving +bodies change their form, and I thought they in general diminished, +but of that I was not certain. In this last observation, at the +twelfth and thirteenth hour I observed it more distinctly; at the same +time remarking that though diminished considerably in size, yet they +increased in specific gravity; especially when their motion was nearly +finished, which generally happened all at once and they sunk to the +bottom, forming a sediment of an ash-colour, plainly perceptible to the +naked eye, and which appeared through the microscope to be composed of +globules adherent to on another, sometimes by threads, and at others +in knots, but always in a regular manner. + +XI. Having procured the seed of a dog, emitted naturally, I observed +that this liquor was clear, and had but little tenacity. I put it in +a phial, and having examined it with a microscope, without diluting +it with water, I perceived moving bodies entirely like those I had +observed in the human semen; they had threads, or tails, perfectly +the same; they were also nearly of the same size; in a word, they +resembled, as perfectly as possible, those I saw in the human liquor, +liquified during two or three hours. I then sought for the filaments +which I had seen in the human liquor, but it was useless; I perceived +only some long threads entirely like those which served as tails to +the globules. These threads were not attached to any globules, nor had +they any motion. Those globules which were in motion, and had tails, +appeared to me to move quicker than those in the human semen: they had +scarcely any horizontal vibrations, but a rolling motion. They were not +in a great number; and, although their progressive motion was stronger, +they took more time to cross the microscope than those I had before +remarked. I observed this liquor for three hours, but perceived no +change: after which I examined it at another time for four hours, and +remarked, that the number of moving bodies diminished by degrees; the +fourth day there was still some, though they were very few, and often +I only found one or two in a drop of liquor. The second day most of +them were deprived of their tails; the third day very few retained +them, yet, at the last day, there still remained some which had them; +the liquor had then deposited a whitish sediment, which appeared to be +composed of immoveable globules, and many threads, that seemed to be +tails separated from the globules. There were also some attached to the +globules, which appeared to be the dead bodies of these little animals, +but whose forms were different from those that moved, for they appeared +larger than the moving globules, or the rest, which remained without +motion at the bottom of the liquor, and appeared to have a fissure or +opening. + +XII. Another time, having taken the seminal liquor of the same dog, I +again perceived the fore-mentioned phenomena; and I saw, besides, in +one of the drops of this liquor, a mucilaginous part, which produced +moving globules, as in the ninth experiment, (_fig. 6._) and these +globules formed a current, and went in ranks like troops. This mucilage +appeared to me animated with an internal inflated motion, which +produced small bloated appearances in different parts, and from whence +issued these bloated forms, or moving globules, with a nearly-equal +swiftness, and in the same direction. The bodies of these globules were +not different from the rest, excepting they had no tails. I observed +that many of them changed their shape, and lengthened considerably, +till they became little cylinders, after which the two extremities of +the cylinders were bloated, and divided into two globules, both moving +and following the same direction as that before they were united. + +XIII. The phial, which contained this liquor, having been broke by +accident, I, a third time, took the liquor of the same dog, but whether +the animal was wearied by too reiterated emissions, or by other +causes, the seminal liquor contained none of the above bodies, but was +transparent and viscous, like the serum of blood; I examined it then, +and at one, two, three, and even twenty-four hours afterwards, but it +presented nothing new: there was not a single moving body to be seen, +nor any mucilage; in a word, nothing that I had seen before. + +XIV. I then opened a dog, and separated the testicles and the adherent +vessels, but I perceived no seminal vesicles, and apparently the seed +in those animals passes directly from the testicles into the urethra. +I found but a small quantity of liquor in the testicles, although the +dog was adult and vigorous. In the small quantity I could collect I +could not discover any bodies that were in motion. I only perceived a +great quantity of very small globules, most of which were motionless, +and some of the smallest had some trifling approximating motion, which +I could not follow, because the drops I gathered were so exceedingly +minute that they dried in two or three minutes after they were placed +in the microscope. + +XV. Having cut the testicles of this dog into two parts, I infused +it in water, and closely sealed up the vessel. Three days after I +examined this infusion, which I made with the design of discovering +whether the flesh did not contain moving bodies, and I saw a great +quantity of moving bodies of a globular and oval form, like those I +had seen in the seminal liquor of the dog, excepting they had not any +threads. They moved in all manner of directions with great swiftness. I +observed these bodies, which appeared animated for some time, and saw +many change their form; I perceived some to lengthen, and others to +contract, while some swelled at both extremities: there were numbers +that were smaller and thicker than the rest; but they were all in +motion, and were about the size and figure of those I have described in +the fourth experiment. + +XVI. The next morning the number of these globules were increased, +but they appeared smaller; their motion was more rapid and irregular; +they had also another appearance with respect to their form and manner +of moving, which seemed confused; the next and several days after, +till the fifteenth day, there were moving bodies in the water, whose +size gradually diminished till they were no Longer visible. The last, +which I perceived with great difficulty, was on the nineteenth and +twentieth days, and they moved with greater rapidity than ever. Upon +the water a kind of pellicle was formed, which appeared to be composed +of the coverings of those moving bodies, small threads, scales, &c. but +entirely motionless; this pellicle, and the moving bodies could not +come into the liquor by means of external air, since the bottle had +been kept carefully sealed. + +XVII. I then successively opened ten rabbits, on different days, to +examine their seminal liquors; the first had not a drop, either in the +testicles or seminal vessels. In the second I was no more successful, +although I was assured he was the father of a very numerous progeny. +I succeeded no better in the third. I then imagined that the presence +of the female might be requisite; I therefore put males and females +into cages so contrived that it was impossible for them to copulate. At +first these endeavours did not succeed; for, on opening two, not a drop +of seminal liquor was to be found; however, in the sixth that I opened, +a large white rabbit, I found, in the seminal vesicles, as much liquor +as could be contained in a teaspoon; this matter resembled calves' +jelly, was nearly transparent, and of a citron colour. Having examined +it with the microscope, I perceived it to resolve, by slow degrees, +into filaments and thick globules, many of which appeared fastened to +each other; but I did not remark any distinct motion in them, only +as the matter liquefied, it formed a kind of current by which these +filaments and globules seemed to be drawn all to one side. I expected +to find this matter take a greater degree of fluidity, but that did not +happen, for, after it was a little liquefied, it dried, and I could +perceive nothing further than what is above mentioned. When this matter +was mixed with water, the latter did not appear to have power to dilute +it. + +XVIII. Having opened another rabbit, I only found a very small quantity +of seminal matter, which was of a colour and consistency entirely +different from the former; it was scarcely tinctured of a yellow hue, +and was much more fluid. As there was but very little, I feared it +would dry too hastily, and therefore mixed it with water: from the +first observation, I did not perceive the filaments I had seen in the +other, but I discovered three globules, all in a trembling and restless +motion; they had also a progressive motion, but it was very slow; some +moved round the others, and most appeared to turn upon their centres. I +could not pursue this observation because the liquor so soon got dry. + +XIX. I opened another of these rabbits, but could not discover any of +this matter; in the seminal vessels of another, I found almost as much +congealed liquor as in XVIIth Experiment: I examined it in the same +manner as the rest, but it afforded me no greater discovery. I infused +the whole I had collected, in almost double the quantity of water, and +after briskly shaking them together, I suffered them to settle for ten +minutes; after which, on inspecting this infusion, I saw the same large +globules as before; there were but few and those very distant from each +other. They had approximating motions with respect to each other, but +they were so slow, as to be scarcely discernable; two or three hours +after, these globules seemed to be diminished, their motion was become +more distinct, and they appeared to turn upon their centres. Although +this trembling motion was more than their progressive, nevertheless +they were clearly seen to change their situation irregularly with +respect to each other. Six or seven hours after the globules were +become still less, and their action was increased: they appeared to me +to be in much greater numbers, and all their motions distinct. The next +morning, there was a prodigious multitude of globules in motion, which +were at least three times smaller than those that at first appeared. +I observed these globules for eight days, and observed that many of +them seemed to join together, after which their motion ceased; this +union, however, appeared to me only superficial and accidental. Some +were larger than others; most were round and spherical, and some of +them were oval. The largest were most transparent, and the smallest +were almost black. This difference did not proceed from the light, for +in whatever situation these small globules were in, they were always of +the same appearance; the motions of the small were much more rapid than +the large ones, and what I remarked most clearly and most generally +in all, was their diminution of size, so that at the eighth day they +were so exceedingly small as to be hardly perceptible, and at last +absolutely disappeared. + +XX. At length having obtained, with no small difficulty, the seminal +liquor of another rabbit, as it would have been conveyed to the female, +I remarked it to be more fluid than that which had been taken from +the seminal vesicles, and the phenomena which it offered were also +very indifferent; for in this liquor there were moving globules and +filaments without motion; and also a kind of globules with threads or +tails, resembling those of a dog or a man, but only appearing smaller +and brisker (_fig. 7._) They passed over the microscope in an instant, +their tails appeared shorter than those of other spermatic animals, +and I own I am not certain whether some of those tails were not false +appearances, produced by the furrows which these moving globules formed +in the liquor, as they moved with too great a rapidity to admit of my +clearly observing them; besides, the liquor, though sufficiently fluid +at first, very speedily dried away. + +XXI. After this I resolved to examine the seminal liquor of a ram; I +applied to a butcher, who supplied me with the necessary parts of at +least twelve or thirteen, directly after they were killed, but I could +not find liquor sufficient for any experiment, either in the epididymis +or seminal vesicles. In the little drops I was able to collect, I only +perceived globules which had no motion. As I made these experiments in +March, I supposed by repeating them in October, the season of female +attachments, I should discover more seminal liquor in these vessels. +I cut many of these testicles in two longitudinally, and collected a +small quantity of liquor, but found nothing more in them. + +[Illustration: _PLATE. II._] + +XXII. I took three of these testicles, of three different rams, cut +each of them into four parts, and put them into separate bottles, with +as much water as was sufficient for them. Securing these bottles from +the admission of air I suffered the infusion to remain for four days, +after which I examined the liquor of each by the microscope, and found +them all replete with an infinity of moving bodies, most part of which +were oval, and the rest globular; they were pretty thick, and resembled +those described in the VIIIth experiment; their motion was neither +brisk, uncertain, nor very rapid, but equal, uniform, and in all +directions. These moving bodies were nearly of the same size in each +liquor, but differed one bottle with the other. They had no tails, nor +were there any filaments or threads in this liquor; during the fifteen +or sixteen days they were retained, they often changed their form, and +seemed successively to throw off their external coverings; they also +became every day smaller, and on the sixteenth day, they were no longer +perceptible. + +XXIII. In the month of October I opened a ram, and found a great +quantity of seminal liquor in the epididymis; having examined it with +the microscope, I perceived an innumerable multitude of moving bodies, +so numerous, that all the liquor seemed to be entirely composed of +them; as it was too thick, I diluted it with water, but I was surprised +to see the motion of these bodies suddenly stop, though I perceived +them very distinctly; having many times repeated the same observation, +I perceived that the water which diluted the seminal liquors of a man, +a dog, &c. seemed to coagulate that of a ram. + +XXIV. I then opened another ram, and in order to prevent the seminal +liquor from coagulating, I permitted the parts of generation to remain +in the body of the animal, and covered it over with warm clothes. By +these precautions I observed the seminal liquor in its fluid state; +it was replete with an infinity of oblong moving bodies, (_fig. 8._) +traversing in various directions; but as soon as the liquor grew cold, +the motion of all these bodies immediately ceased. I diluted the +liquor with warm water, when the motion of the small bodies remained +for three or four minutes. The quantity of these moving bodies was so +great in this liquor, that although diluted, they nearly touched each +other. They were all of the same size and form, but none of them had +tails. Their motion was not very quick, and when it stopped by the +coagulation of the liquor, they did not change their form. + +XXV. As I was persuaded, not only by my own theory, but also by the +observations of all those who had made experiments before me, that the +female, as well as the male, has a seminal and prolific liquor; and, +as I had no doubt, but the reservoir of this liquor was the glandular +body of the testicle, where prejudiced anatomists attempted to find the +egg, I purchased several dogs and bitches, and some male and female +rabbits, which I kept separate from each other; and in order to have a +comparative object with the liquor of the female, I again observed the +seminal liquor of a dog, and discovered there the same moving bodies as +described in the XIth experiment. + +XXVI. While I was thus occupied, a bitch was dissected which had been +four or five days in heat, and had not received the dog. The testicles +were readily found, and on one of them I discovered a red, glandular, +prominent body, about the size of a pea, which perfectly resembled +a little nipple; on the outside was a visible orifice formed by two +lips; one of which jutted out more than the other. Having introduced a +small instrument into this orifice, a liquor dropped from it, which we +carefully caught to examine with the microscope. The surgeon replaced +the testicles in the body of the animal, which was yet alive, in order +to keep them warm. I then examined this liquor with a microscope, and, +at the first glance, had the satisfaction to see moving bodies with +tails, exactly like those I just before saw in the seminal liquor +of the dog. (_fig. 9._) Messrs. Needham and Daubenton, who observed +them with me, were so surprized at this resemblance, that they could +scarcely believe but that these spermatic animals were the same, +and thought I had forgotten to change the table of the microscope, +or that the instrument with which we had gathered the liquor of the +female, might before have been used for the dog. Mr. Needham then +took different instruments, and having obtained some fresh liquor, +he examined it first, and saw there the same kind of animals, and +was convinced, not only of the existence of spermatic animals in the +seminal liquor of the female, but likewise of their resemblance to +those of the semen of the male. We repeated it ten times at least, in +different drops of the same liquor, without perceiving the smallest +variation in the phenomena. + +XXVII. Having afterwards examined the other testicle, I found a +glandular body in its growing state; it had not any external orifice, +was much smaller, and not so red as the first. Having opened it, I +found no liquor; but only a small fold in the internal part, which I +judged to be the origin of the cavity that was to contain the liquor. +This second vesicle had some very small lymphatic vesicles externally. +I pierced one of them with a lancet, and a clear and limpid liquor +flowed out, which I examined with the microscope; it contained nothing +similar to that of the glandular body; it was a clear matter, composed +of small globules, which were motionless. Having often repeated this +observation, I was assured, that this liquor in the vesicles was only +a kind of lymph, which contains nothing animated, or similar to that +seen in the female seed, which is formed and perfected in the glandular +bodies. + +XXVIII. Fifteen days after I opened another bitch that had been in +heat seven or eight days, but had not received the dog. I found the +testicles contiguous to the extremities of the horns of the matrix; +these horns were very long, their external tunic surrounded the +testicles, and they appeared covered with that membrane like a cowl. +In each testicle I found a glandular body in its full maturity. The +first was half open, and there was a passage which penetrated into the +testicle, and which was replete with seminal liquor; the second was +somewhat more large and prominent, and the orifice, or canal, which +contained the liquor was below the nipple. I took these two liquors, +and having compared them, found them perfectly alike. The seminal +liquor of the female is at least as liquid as that of the male. Having +afterwards examined the two liquors with the microscope, I perceived +the like moving bodies, (_fig. 10._) and the same phenomena, as in the +seminal liquor of the other. I saw besides many globules which moved +very briskly, and endeavoured to disengage themselves from the mucilage +that surrounded them: there was a great quantity of them as in the seed +of the female. + +XXIX. From these glandular bodies I pressed out all the liquor, and +having collected it, I found enough to last for four or five hours +observations. I remarked that it deposited somewhat to the bottom, or +at least began to thicken. I took one drop of this, which was thicker +than the rest, and having put it on the microscope, perceived that the +mucilaginous part of the seed was condensed, and formed a continued +net-work. On the external border of this net-work, there was a torrent, +or current, composed of globules, which moved with rapidity. These +globules were lively, active, and appeared to be disengaged from their +mucilaginous covering, and their tails. This stream perfectly resembled +the course of the blood in small transparent veins; for they appeared +not only to be animated by their own powers, but also to be impelled +by a common force, and constrained to follow in a herd. From this +experiment, and the XIth and XIIth, I concluded, that when the fluid +begins to coagulate and thicken, these active globules break and tear +their mucilaginous coverings, and escape by that side where the liquor +remains most fluid. These moving bodies had then neither threads nor +tails; they were for the most part oval, and appeared to be flat at the +bottom, for they had no rolling motion. + +XXX. The horns of the matrix were externally soft; I opened them +longitudinally, and only found a very small quantity of liquor, which, +upon examination, appeared to contain the same as that pressed from the +glandular substance of the testicle. These glandular bodies are placed +so as easily to sprinkle this liquor on the horns of the matrix; and +I am persuaded that, as long as the amorous season remains, there is +a continual dropping of this liquor from the glandular substance into +the horns of the matrix; that this dropping remains till the glandular +substance has emptied the vesicles; it then becomes fluid by degrees, +is effaced, and only leaves a little reddish cicatrice on the external +part of the testicle. + +XXXI. I took this seminal liquor of the female, with the same quantity +of that just emitted from the male, and mixed them together, and having +examined this mixture with the microscope, I perceived nothing new, the +liquor remaining the same, and the moving bodies were so similar, that +it was impossible to distinguish those of the male from those of the +female; I only thought their motion appeared a little slackened. + +XXXII. Having dissected a young bitch that had never been in heat, I +only discovered a small protuberance on one of the testicles, which +I supposed to be the origin of a glandular body. The surface of the +testicles was smooth and even, and the lymphatic vessels could scarcely +be seen externally, until the tunic, which covered the testicles, was +separated; but these vesicles were not considerable, and contained but +a small quantity of liquor, in which I could only perceive some little +globules without any motion. + +XXXIII. In another bitch, which was younger, and only three or four +months old, there was no appearance of glandular bodies on the +testicles; they were white, smooth, and covered with a cowl like the +rest. There were some little vesicles which contained little or no +liquor; and it was with great difficulty we could perceive any vesicles +externally. I compared one of these testicles with that of a young +dog of nearly the same age, and they appeared internally of a fleshy +nature, and perfectly similar. I do not mean to contradict what some +anatomists have said concerning the testicles of dogs, but only that +the appearance of the internal substance of the female testicles is +like that of the males, when the glandular substances are not yet +grown. + +XXXIV. The genital parts of a cow, which had been just killed, was +sent to me, covered over with hot cloths, and put into a basket with +a live rabbit, which likewise squatted on a cloth at the bottom, so +that I received them almost as warm as when taken out of the body. I +immediately inspected the testicles, and found them of the size of +a hen's, or, at least, a pigeon's egg. One of these testicles had a +glandular body, about the size of a pea, protuberating outwardly like a +small nipple, but it was not pierced, nor had any external orifice: it +was close and hard. I pressed it with my fingers, but no liquor issued +from it. I observed, before this testicle was dissected, there were +two other glandular substances at a distance from the other; but these +were just begun to grow; their colour was a whitish yellow, whereas +that which seemed to have pierced the membrane of the testicle was of +a rose colour. I opened this last, and examined it with the greatest +attention, but could not discover that it contained any liquor, I +therefore judged that it was far distant from its maturity. + +XXXV. The other testicle had no glandular body which had pierced the +common membrane that covered the testicle, there were only two small +ones, which began to form a little protuberance below this membrane. +I opened both of them but no liquor issued therefrom: they were hard, +whitish, and with a little yellow tint; each of them had four or five +lymphatic vesicles, very easily distinguishable on their surface, and +appearing transparent. I judged they contained a quantity of liquor, +and having pierced them with a lancet, the liquor issued out to some +inches distance. I collected a sufficient quantity of this liquor to +observe it easily; I only saw some very minute immoveable globules; and +although I continued my examination for two days, I neither discovered +alteration, change, nor motion, therein. + +XXXVI. Eight days after, two more genital parts were brought to me +in the same mode as the last. I was assured that one was taken from +a young cow that had never calved, and the other from one that had +had several, but was not old. I first examined the testicles of the +latter, and on one of them I found a glandular substance, as large and +as red as a cherry, which appeared a little soft towards the nipple. I +distinguished three small holes, in which a hair might be introduced. +Having pressed this substance with my fingers a small quantify of +liquor issued, which I placed on the table of a microscope, and had the +satisfaction to see some moving globules there, but quite different +from those which I had seen in other seminal liquors (_fig. 11._). +These globules were obscure and little; their progressive motion, +although distinct, was, nevertheless, very slow. The liquor was not +thick; the little globules had no appearance of threads, or tails, and +they were not all in motion. This is all I was able to perceive in the +liquor this glandular substance afforded me, for although I pressed +it again, it only afforded a less quantity, mixed with blood. I again +discovered it in the small moving globules, but they seemed to be at +least four times smaller than the sanguinary globules. + +XXXVII. This glandular body was situate at one of the extremities by +the side of the horn of the matrix, and the liquor, which it prepares, +must fall upon this horn; nevertheless, on opening this horn I found +no material quantity of liquor. This glandular body penetrated very +forward in the testicle, and occupied more than a third of its internal +substance. I opened them longitudinally, and found a pretty large +cavity, but entirely void of any liquor. At some distance from this +glandular body there was a small one of the same kind, about the size +of a lentil. There were also two small cicatrices, about the same size, +which formed two small indentations, of a deep red colour: they were +the remains of obliterated glandular bodies. Having afterwards examined +the other testicle, I counted four cicatrices and three glandular +bodies; the foremost of which had pierced the membrane, was of a flesh +colour, and the size of a pea. It was solid, and without any orifice +or liquor: the two others were smaller, harder, and of a deep orange +colour. On the first testicle only two or three apparent lymphatic +vesicles remained. I counted eight on the external part, and having +examined the liquor of these vesicles I perceived only a transparent +matter, without any moving bodies. + +XXXVIII. I then examined the testicles of the young cow which had not +calved, which, notwithstanding, were something larger than the other, +but it is true there were no cicatrices on either of them; the one +was smooth and very white, and a number of lymphatic vesicles were +sprinkled about it, but there was not the least mark of a glandular +body. On the other testicle I perceived the marks of two glandular +substances, the one had just began to grow, and the other was the size +of a pea; there was also a great number of lymphatic vesicles, which I +pierced with a lancet, but the liquor did not contain any thing; having +pierced the two small glandular bodies some blood alone issued thereout. + +XXXIX. I divided each testicle of both cows into four parts, and, +having put them into separate phials, I poured as much water on as +would cover them, and after having closely corked them up, I suffered +to infuse for six days; I then examined these infusions, and discovered +an innumerable quantity of living moving bodies (_fig. 12._); they +were all, in these infusions, extremely small, moved with a surprising +rapidity in all directions. I observed them for three days, and they +always appeared to diminish, till at last, on the third day, they +entirely disappeared. + +XL. The following day they brought to me the genital parts of three +more cows. I immediately searched the testicles to find one where the +glandular substance was in perfect maturity; but in two of them I +only discovered some growing glandular substances on the testicles. +I could not learn whether these cows had calved or not, but there +was a great appearance they had all been in season, for there were +a great number of cicatrices on all these testicles. In the third I +found a testicle, on which was a glandular substance, as thick and as +red as a cherry; it was inflamed, and seemed to be in full maturity. +Its extremity was a nipple, with a small hole; I pressed it a little +between my fingers, and a quantity of liquor issued out. I found in +this liquor moving globules, exactly like those in the liquor pressed +from the glandular body of the other cow, I have before spoken of in +experiment XXXVI. They appeared to be more numerous, their progressive +motions were not so slow, and their size larger. Having observed them +for some time I perceived some to lengthen and change their form. I +then introduced a very fine instrument into the little hole of the +glandular substance, and having opened it I found the internal cavity +replete with liquor; this liquor offered me the same phenomena, and the +same moving globules, as I before observed in experiment XXXVI. with +either filaments, threads, or tails attached to them. The liquor of +the vesicle presented me with nothing more than nearly a transparent +matter, which did not contain one moving thing. + +XLI. At different times they brought me the genitals of several other +cows. In some I found the testicles loaded with an almost mature +glandular substance; in others they were of different growths, and +I remarked nothing new, excepting that in the two testicles of two +different cows I perceived the glandular substance in a decayed state; +the base of one was as broad as the circumference of a cherry; the +extremity of the nipple was soft, wrinkled, and shrivelled; the two +small holes were very perceptible, from whence the liquor had flowed. +With some difficulty I introduced a small hair, but there was no liquor +in the canal, nor in the internal cavity, which was still to be seen. +The flaccidity of these glandular substances begins, therefore, at +the most external part, or extremity of the nipple. They diminish at +first in height, and afterwards in breadth, as I observed in another +testicle, where this glandular substance had diminished more than three +fourths. + +XLII. As the testicles of doe rabbits, as well as the glandular bodies +formed there, are very small, I could observe nothing very exactly +with respect to their seminal liquor. I only discovered, that the +testicles of doe rabbits are different, and that none of those I saw +resembled what De Graaf represents in his engravings; for the glandular +substances did not enclose the lymphatic vesicles; and I never saw a +pointed end, as he has depicted them. + +XLIII. I found on the testicles of some cows a kind of bladders, +replete with transparent liquor. I remarked they were of different +sizes, the largest about that of a pea; they were fastened to the +external membrane of the testicle by a strong membraneous pedicle, +as was also another, still smaller; and a third, nearly of the same +size as the second, appeared to be only a lymphatic vesicle, much +more apparent than the rest. I imagined these bladders, which the +anatomists have called _hydatides_, might possibly be of the same +nature as the lymphatic vesicles of the testicles, for having examined +the liquor they contained I found it to be perfectly similar; it was a +transparent and homogeneous liquor, which did not contain one moving +substance. + +XLIV. At the same time I made observations on the liquor in an oyster; +on the water in which pepper had been boiled; on the water wherein +pepper had been only infused; and on the water wherein I had put some +vegetable seed; the bottles which contained these waters were firmly +closed, and in two days I perceived in the oyster liquor a great +quantity of oval and globular substances, which seemed to swim like +fish in a pond, and had all the appearance of being animals; however +they had no limbs nor tails, but were very large, transparent, and +visible. I perceived them change their forms, and become smaller for +seven or eight days successively; and at length I and Mr. Needham +observed animals similar to those in an infusion of jelly of roast +veal, which had been also very exactly corked; so that I am persuaded +they are not real animals, at least according to the received +acceptation of the words, as we shall hereafter explain. + +The infusion of the seed presented an innumerable multitude of moving +globules which appeared animated like those of the seminal liquors, +and in the infusions of the flesh of animals: these were also large, +and in violent motion during the first days, but they diminished by +degrees, and disappeared only from their minuteness. + +I perceived the same thing, but later, in the liquor wherein pepper +had been boiled, and the like, though still later, in that which had +not boiled; from hence I supposed that what is called fermentation may +possibly be only the effect of the motion of these organical parts +of animals and vegetables; and in order to see what difference there +was between this kind of fermentation and that of minerals, I placed +a little powdered stone on the microscope, and sprinkled thereon a +drop of aquafortis, which however produced a different phenomena, +consisting of great balls, which ascended to the surface, and almost +instantaneously obscured the focus of the microscope: this was a +dissolution of the grosser parts, which being completed it became +motionless, and had not the smallest resemblance to the other infusions +I had observed. + +XLV. I examined the seminal liquor in the roes of different fish; such +as carp, tench, barbel, &c. which I took out while they were living, +and having observed three different liquors with great attention, I +perceived a great quantity of obscure globules, all in motion. I took +several more of these fish alive, and with my fingers gently compressed +that part of the belly where this liquor is emitted; and in that which +I obtained, I perceived an infinity of moving globules therein, very +black and very small. + +XLVI. Before I finish this chapter I shall relate the experiments of +Mr. Needham on the seed of a kind of cuttle fish, called calmar. This +able naturalist having sought for spermatic animals in the milts of +many different fish, found them in the roe of a calmar, apparent to +the naked eye. During the summer he dissected calmars at Lisbon, but +found no appearance of any roe, nor any reservoir which appeared to be +destined for the reception of the seminal liquor; and it was in the +middle of December that he began to discern the first traces of a new +vessel replete with a milky juice. This reservoir increased, and the +seed which it contained was diffused very abundantly. By examining this +liquor with the microscope, he perceived only small opaque globules, +which floated in a kind of serous matter, without the least appearance +of life. But some time after, in the milt of another calmar, he found +these organic parts completely formed; they seemed like spiral springs +shut up in a kind of transparent case. They appeared as perfect at +first as they did at last, excepting that by degrees they contracted +and formed a kind of screw. The lid of the case was a species of +valve that opened outwardly, and by which all the contents might +issue; it contained another valve, a barrel, and a spongy substance; +therefore the whole machine consisted in an external, transparent, and +cartilaginous case, whose upper extremity is terminated by a round +head, formed by the case itself, and which performs the office of a +valve. In this external case is contained a transparent tube, which +encloses the spring, piston, or valve, barrel, or spongy substance. +The screw occupies the upper part of the tube and case, the piston and +barrel are placed in the middle, and the spongy substance occupies +the lower part. These machines pump up the lacteal liquor, of which +the spongy substance is full; and before the animal spawns, the whole +milt is no more than a composition of these organic parts, which have +absolutely pumped up the lacteal liquor. As soon as these little +machines are taken from the body of the animal, and deposited either +in water, or held in the air, they begin to act; the spring ascends, +followed by the piston, the barrel, and the spongy substance which +contains the liquor; and as soon as the spring and the tube which +contain it begin to quit the case, the spring folds up; and all that +remains within begins to move, till the spring, the sucker, &c. are +entirely come out: as soon as that is done, the remainder immediately +follow, and the lacteal liquor, which has been pumped out, and which +was contained in the spongy substance flows out by the barrel. + +As this observation is very singular, and incontestibly proves that +the moving bodies found in the milt of the calmar are not animals, but +simple machines, a kind of pumps, I have deemed it necessary to give +Mr. Needham's own words.[Q] + +[Q] See New Discoveries made with the microscope by Mr. Needham, chap. +vi. Leyden, 1747. + +"When the small machines, he says, are arrived to their perfect +maturity, many of them act the moment they are in the open air; +nevertheless most of them may be commodiously placed, so as to be +seen with a microscope, before their action begins; and even to make +them act, the upper extremity of the external case must be moistened +with a drop of water which then begins to expand, while the two small +ligaments which issue from the case twist and turn in different +manners: at the same time, the screw ascends slowly, the volutes, which +are at its upper end, approach and act against the top of the case: +those at the bottom also advance, and seem to be continually followed +by others which come from the piston. I say, they seem to be followed, +because I do not think they are so effectually, but only a deception +produced by the nature and motion of the screw. The piston and barrel +also follow the same direction, extend lengthways, and at the same time +move towards the top of the case, which is perceived by the vacuum +at the bottom. As soon as the screw, with the tube in which it is +enclosed, begins to appear externally from the case, it folds, because +it is retained by its two ligaments: nevertheless, all the internal +contents continue to move gently and gradually, until the screw, +piston, and bladder, are entirely come out. When that is done, the rest +follow directly after. The piston separates from the barrel, and the +apparent ligament, which is below the latter, swells and acquires a +diameter equal to that of the spongy substance which follows it. This, +although much larger than when in the case, becomes still five times +longer than before. The tube which incloses it all is straightened in +its middle, and forms two kinds of knots, about a third of its length +distant from each extremity: the semen then flows through, and is +composed of small opaque globules, which float in a serous matter, +without shewing any signs of life, and which are precisely such as I +have said to have seen them when they were diffused in the reservoir +of the milt. In the figure, the part between the two knots seems to +be broken: when it is examined attentively, we find that what causes +it to appear as such, is, that the spongy substance with in the tube +is broken in nearly equal pieces, which the following phenomena will +clearly prove. Sometimes it happens, that the screw and the tube break +by the piston, which remains in the barrel; then the tube closes in +a moment, and takes a conical figure, by contracting, as much as it +is possible, above the end of the screw, which demonstrates its great +elasticity in that part: and the manner in which it accommodates itself +with the figure of the substance it incloses, when it receives the +least change, proves, that it is equal in every other respect." + +Mr. Needham from this conceives that we might imagine the actions +of all this machine were owing to the spring of the screw, but he +proves, by many experiments, that the screw, on the contrary, only +obeys a power which resides in the spongy part. As soon as the screw +is separated from the rest, it ceases its action, and loses all its +activity. The author afterwards makes this reflection on this singular +machine: + +"If, says he, I had seen the animalcule pretended to be in the semen of +living animals, perhaps I might be in a condition to determine whether +they are really living creatures, or simple machines prodigiously +minute, and which are in miniature, what the vessels of the calmar are +in the great." + +By this, and some other analogies, Mr. Needham concludes, there is a +great appearance that the spermatic worms of other animals are only +organized bodies and machines, like to those of the calmar, whose +actions are made at different times; "for, says he, let us suppose, +that in the prodigious number of spermatic worms seen on the table +of a microscope, there are some thousands which act at the same time, +that will be sufficient to shew us, they are all alive. Let us also +conceive, adds he, that the motion of these spermatic worms remains, +like that of the machines of the calmar, about half a minute; then the +succession of action of these small machines, will remain a long time, +and the pretended animals will appear to decrease successively. Besides +why should the calmar alone have machines in its seed, whereas every +other animal has spermatic worms, and real animals? Analogy is here +of such great weight, that it does not appear possible to refuse it." +Mr. Needham likewise very justly remarks, that even the observations +of Leeuwenhoek, seems to indicate that the spermatic worms have a +great resemblance with the organized bodies in the seed of the calmar. +"I have, says Leeuwenhoek, speaking of the cod, taken those real +substances for hollow and extended animalcule, because they were four +times as large as the living animalcule." And in another part, "I have +remarked, he says, speaking of the seed of a dog, that the animalcules +often change their form, especially when the liquor in which they +float evaporates. The progressive motion does not extend above the +diameter of a hair."[R] + +[R] See Leeuwenh. Arch. Nat. page 306, 309, 310. + +After considering all these circumstances Mr. Needham conjectures, +that the supposed spermatic animals might possibly be only natural +machines, substances much more simply organized than the bodies of +animals. I have seen with the microscope, these machines in the calmar, +and the description he gives of them, is very faithful and exact. His +observations then shew us, that the seminal liquor is composed of +parts which seek to be organized; that it, in fact, produces organized +substances, but that they are not as yet, either animals or organized +substances, like the individual which produced them. We might suppose, +that these substances are only instruments which serve to perfect the +seminal liquor, and strongly impel it; and that it is by their brisk +and internal action, that it most intimately penetrates the seminal +liquor of the female. + + + + +CHAPTER VII. + +COMPARISON OF MY OBSERVATIONS WITH THOSE OF LEEUWENHOEK. + + +Although I made the preceding experiments with all the circumspection +possible; and although I repeated them a number of times, I am +persuaded that many things escaped my notice; I have only related what +I saw, and what all the world may see, with a little art and much +practice. In order to be free from prejudices, I endeavoured to forget +what other naturalists asserted to have seen, conceiving that by so +doing, I should be more certain of only seeing in fact what really +appeared; and it was not till after I had digested my observations, +that I compared them with those of Leeuwenhoek, &c. I by no means +pretend to have greater abilities in microscopical observations than +that great naturalist, who passed more than sixty years in making +various experiments. + +Notwithstanding the authority his observations may justly claim, it +is surely permitted to examine and compare others with them. Truth +can only be gained by such examinations, and errors discovered, +particularly as we do it without any partiality, and in the sole view +of establishing something fixed and certain on the nature of those +moving bodies seen in the seminal liquors. + +In November 1677, Leeuwenhoek, who had already communicated to the +Royal Society of London many microscopical observations on the optic +nerve, the blood, the juice of the plants, the texture of trees, +rain-water, &c. addressed to Lord Brouncker, President of the Society, +in the following words: "Postquam Exc.[S] &c. Dominus Professor +Cranen me visitatione sua sępius honorarat, litteris rogavis, Domino +Ham concrato suo, quasdam observationum mearum, videndas darem. Hic +dominus Ham me secundo invisens, secum in laguncula, vitrea semen +viri, gonorrhęa laborantis, sponte destillatum, attulit, dicens, se +post paucissimas temporis minutias (cum materia ilia jam in tantum +esset resoluta ut fistulę vitreę immitti posset) animalcula viva in +eo observasse, quę caudam & ultra 24 horas non viventia judicabat; +idem referebat se animalcula observasse mortua post sumptam ab ęgroto +therebintinam. Materiam prędicatam fistulę vitreę immissam, pręsente +Domino Ham, observavi, quasdamque in ea creaturas viventes, at post +decursum 2 aut 3 horarum eamdem solus materiam observans, mortuas vidi. + +[S] See Phil. Trans. No. 141, page 1041. + +"Eamdem materiam (semen virile) non ęgroti alicujus, non diuturna +conservatione corruptam, vel post aliquot momenta fluidiorem factam, +sed sani viri statim post ejectionem, ne interlabentibus quidem sex +arterię pulsibus, sępiuscule observavi, tantamque in ea viventium +animalculorum multitudinem vidi, ut interdum plura quam 1000 in +magnitudine arenę sese moverent; non in toto semine, sed in materia +fluida crassiori adhęrente, ingentem illam animalculorum multitudinem +observavi; in crassiori vero seminis materia quasi sine motu jacebant, +quod inde provenire mihi imaginabar, quod materia illa crassa ex tam +variis cohęreat partibus, ut animalcula in ea se movere nequirent; +minora globulis sanguini ruborem adferentibus hęc animalcula erant, ut +judicem, millena millia arenam grandiorem magnitudine non ęquatura. +Corpora corum rotunda, anteriora obtusa, posteriora ferme in aculeum +desinentia habebant; cauda tenui longitudine corpus quinquies sexiesve +excedente, & pellucida crassitiem vero ad 25 partem corporis habente +prędita erant, adeo ut ea quoad figuram cum cyclaminis minoribus, +longam caudam habentibus, optime, comparare queam; motu caudę +serpentino, aut ut anguillę in aqua natantis progrediebantur; in +materia vero aliquantulum crassiori caudam octies deciesve quidem +evibrabant antequam latitudinem capilli procedebant. Interdum mihi +imaginabar me internoscere posse adhuc varias in corpore horum +animalculorum partes, quia vero continuo eas videre nequibam, de iis +tacebo. His animalculis minora adhuc animalcula, quibus non nisi +globuli figuram attribuere possum, permissa erant. + +"Memini me ante tres aut quatuor annos, rogatu Domini Oldenburg, B. M. +semen virile observasse, & prędicta animalia pro globulis habuisse; +sed quia fastidiebam ab ulteriori inquisitione, & magis quidem a +descriptione, tunc temporis eam omisi. Jam quoad partes ipsas, ex +quibus crassam seminis materiam, quoad majorem sui partem consistere +sępius cum admiratione observavi, ea sunt tam varia ac multa vasa, imo +in tanta multitudine hęc vasa vidi, ut credam me in unica seminis gutta +plura observasse quam anatomico per integrum diem subjectum aliquod +secanti occurrant. Quibus visis, firmiter credebam nulla in corpore +humano jam formato esse vasa, quę in semine virili bene constituto non +reperiantur. Cum materia hęc per momenta quędam aėri fuisset exposita, +prędicta vasorum multitudo in aquosam magnis oleaginosis globulis +permistam materiam mutabatur, &c." + +The Secretary of the Royal Society, in answer to this letter, says, +that it would be proper to make the like experiments on the seed of +other animals, as dogs, horses, &c. not only to form a better judgment +on the first discovery, but to know the differences which might be +found in the number, and the figure of those animalcules. And with +relation to the vessels of the thickest part of the seminal liquors, +he greatly doubts they were only filaments without any organization, +"quę tibi videbatur vasorum congeries, fortassis seminis sunt +quędam filamenta, haud organice constructa, sed dum permearunt vasa +generationi inservientia in istiusmodi figuram elongata. Non dissimili +modo ac sępius notatus sum salivam crassiorem ex glandularum faucium +foraminibus editam quasi e convolutis fibrilis constantem."[T] + +[T] See the Secretary's answer to Leeuwenhoek's Letter in the Phil. +Trans. No. 141, page 1043. + +Leeuwenhoek answered him on the 18th of March, 1678, in the following +words: "Si quando canes coeunt marem a foemina statim seponas materia +quędam tenuis & aquosa (lympha scilicet spermatica) e pene solet +paulatim exstillare; hanc materiam numerosissimis animalculis repletam +aliquoties vidi, eorum magnitudine quę in semine virili conspiciuntur, +quibus particulę globulares aliquot quinquagies majores permiscebantur. + +"Quod ad vasorem in crassiori seminis virilis portione spectabilium +observationem attinet, denuo non semel iteratam, saltem mihimetipsi +comprobasse videor; meque omnino persuasum habeo, cuniculi, canis, +felis, arterias venasve fuisse a peritissimo anatomico haud unquam +magis perspicue observatas, quam mihi rasa in semine virili, ope +perspicilli, in confectum venere. + +"Cum mihi prędicta vasa primum innotuere, statim etiam pituitam, tum +& salivam perspicillo applicavi; verum his minime existentia animalia +frustra quęsivi. + +"A cuniculorum coitu lymphę spermaticę guttulam, unam et alteram, +e femella exstillantem, examini subjeci, ubi animalia prędictorum +similia, sed longe pauciora, comparuere. Globuli item quam plurimi, +plerique magnitudine animalium, iisdem permisti sunt. + +"Horum animalium aliquot etiam delineationes transmisi, figura _a_ +(_plate 3._) exprimit corum aliquot vivum (in semine cuniculi arbitror) +eaque forma qua videbatur, dum aspicientem me versus tendit. A B C, +capitulum cum trunco indicant; C D, ejusdem caudam, quam pariter ut +suam anguilla inter natandum vibrat. Horum millena millia, quantum +conjectare est, arenulę majoris molem vix superant, (_fig. b, c, d,_) +sunt ejusdem generis animalia, sed jam mortua. + +[Illustration: _PLATE. III._] + +"(_Fig. e._) Delineatur vivum animalculum, quemadmodum in semine canino +sese aliquoties mihi attentius intuenti exhibuit. E F G, caput cum +trunco indigitant, G H ejusdem caudam, (_fig. f, g, h,_) alia sunt in +semine canino quę motu & vita privantur, qualium etiam vivorum numerum +adeo ingentem vidi, ut judicarem portionem lymphę spermaticę arenulę +mediocri respondentem, eorum ut minimum decena millia continere." + +By another letter written to the Royal Society, the 31st of May, +1678, Leeuwenhoek adds, "Seminis canini tantillum microscopio +applicatum iterum contemplatus sum, in eoque antea descripta animalia +numerosissime conspexi. Aqua pluvialis pari quantitate adjecta, iisdem +confestim mortem accersit. Ejusdem seminis canini portiuncula in vitreo +tubulo uncię partem duodecimalem crasso servata, sex & triginta horarum +spatio contenta animalia vita destitua pleraque, reliqua moribunda +videbantur. + +"Quo de vasorum in semine genitali existentia magis constaret, +delineationem eorum aliqualem mitto, ut in figura ABCDE, (_fig. i._) +quibus literis circumscriptum spatium arenulam mediocrem vix superat." + +I have copied these first remarks of Leeuwenhoek from the Philosophical +Transactions, because, in matters of this kind, observations made +without any systematical view are those which are the most faithfully +described, and even this able naturalist no sooner formed a system on +spermatic animals, than he began to vary in essential points. + +It is evident by the above dales, that Hartsoeker is not the first who +published, if he was the first who discovered spermatic animals. In +the Journal de Sēavans, in the year 1774, there is a letter from Mr. +Huguens, on the subject of a microscope, made by one small ball of +glass, with which he asserts he perceived animals in the water, wherein +pepper had been infused for two or three days, as Leeuwenhoek before +had observed with the like microscopes, but whose balls were not so +minute. "There are also other seeds, he continues, which engender such +animals, as coriander seeds, &c. and I have seen the same thing in the +pith of the birch tree, after having kept it for four or five days; and +some have observed them in the water where nutmegs and cinnamon have +been soaked. These animals may be said to engender from some corruption +or fermentation: but there are others which must have a different +origin; as those in the seed of animals, which seem in such great +numbers, as to be almost composed of them; they are all transparent, +have a quick motion, and their figures are like the tadpole." + +Huguens does not mention the author of this discovery; but in the +Journal of the 29th of August in the same year, there is an extract +of a letter of M. Hartsoeker, in which he gives the method of forming +these glass balls by means of the flame of a lamp; and the author of +the Journal says, "By this method he has discovered that little animals +are engendered in urine which has been kept for some days, and have +the figure of little eels: he found some in the seed of a cock, which +appeared of the same form, but quite different from those found in the +seed of other animals, which resemble tadpoles, or young frogs, before +their legs are formed." The author seems to attribute the invention to +Hartsoeker; but if we reflect on the uncertain manner in which it is +there represented, and on the particular manner in which Leeuwenhoek +speaks in his letter, written and published above a year before, we +must allow him to be the first who made this observation; but between +them a contest took place as to the discovery which has never been +decided. Be this as it will, Leeuwenhoek was undoubtedly the first +inventor of the microscope, whose focuses are balls of glass formed by +the flame of a lamp. But to return to his observations. + +I shall first remark, that what he says of the number and motion of +these pretended animals is true; but the figure of the body is not +always the same as he describes it: sometimes the part which precedes +the tail is round and at others long; often flat, and frequently +broader than it is long, &c. and with respect to the tail, it is often +much larger and shorter than he asserts. The motion of vibrations +which he gives to the tail, and by means of which he pretends that the +animalcules advance progressively in this fluid, has never appeared +to me as he has described it. I have seen these moving substances +make eight or ten oscillations from the right to the left, or vice +versa, without advancing the breadth of a hair; and I have even seen +many more which could not advance at all; because this tail, instead +of being of any assistance to them was, on the contrary, a thread +attached either in the filaments or mucilaginous parts of the liquor, +and rather retained the moving substance like as a thread fastened to +the point retains the ball of a pendulum; and when this tail had any +motion, it only resembled a thread which forms a curve at the end of +an oscillation. I have seen these threads, or tails, fastened to the +filaments which Leeuwenhoek stiles vessels; I have seen them separate +after many reiterated efforts of the moving bodies; I have seen them +at first lengthen, then diminish, and at last totally disappear. I +therefore think these tails should be considered as accidental parts, +and not as essential to the bodies of these pretended animals. But +what is most remarkable, Leeuwenhoek precisely says, in his letter +to Lord Brouncker, that, besides these animals that had tails, there +were also smaller animals in this liquor, which had no other form than +that of a globule. "His animalculis (caudatis scilicet) minora adhuc +animalcula, quibus non nisi globuli figuram attribuere possum, permista +erant." This is the truth; but after Leeuwenhoek had advanced that +these animals were the only efficient principle of generation, and that +they were transformed into human figures, he has only regarded those +as animals which had tails; and as it was consistent for animals that +were transformed into human figures, to have a constant form, he never +afterwards mentions those smaller animalcules without tails; and I +was greatly surprised, on comparing the copy of this letter with that +he published twenty years after, in his 3d volume, where, instead of +the above words, the following are found: "Animalculis hisce permistę +jacebant alię minutiores particulę, quibus non aliam quam globulorum +seu sphęricam figuram assignare queo;" which is quite different. A +particle of matter to which he attributes no motion, is very different +from an animalcule: and it is astonishing that Leeuwenhoek, in +copying his own works, has altered this essential article. What he +adds immediately after likewise merits attention: he says, that by +the desire of Mr. Oldenburg he had examined this liquor three or four +years before, when he took these animalcules for globules; that is, +there are times when these pretended animalcules are no more than +globules, without any remarkable motion, and others when they move with +great activity; sometimes they have tails, and at others they have +none. Speaking in general of spermatic animals he says, "Ex hisce +meis observationibus cogitare coepi, quamvis antehac de animalculis +in seminibus masculinis agens, scripserim, me in illis caudas non +detexisse, fieri tamen posse ut illa animalcula ęque caudis fuerint +instructa ac nunc comperi de animalculis in gallorum gallinaceorum +semine masculino;" another proof that he has often seen spermatic +animals of all kinds without tails. + +In the second place we must remark, that the filaments which are +seen in the seminal liquor before it is liquefied were discovered by +Leeuwenhoek, and that in his first observations, before he had made +any hypothesis on spermatic animals, he considered these filaments as +veins, nerves, and arteries; and firmly believed all the parts and +vessels of the human body might clearly be seen in the seminal liquor. +This opinion he persisted in, in defiance of the representations +which Oldenburg made to him on this subject from the Royal Society: +but as soon as he thought of transforming these pretended spermatic +animals into men, he no longer mentioned these vessels; and instead +of looking on them as nerves, arteries, and veins, of the human body +already formed in the seed; he did not even attribute to them the +functions they really possess, the producing of these moving bodies: +and he says, vol. I. p. 7, "Quid fiet de omnibus illis particulis seu +corpusculis pręter illa animalcula semini virili hominum inhęrentibus? +Olim & priusquam hęc scriberem, in ea sententia fui, prędictas strias +vel vasa ex testiculis principium secum ducere, &c." And in another +part he says, that if he had formerly written any thing on the subject +of these vessels found in the seed, we must pay no attention to it. + +[Illustration: _PLATE. IV._] + +We shall observe in the third place, that if we compare the figures +_a, b, c, d_, (PLATE III.) copied from the Philosophical Transactions, +with those which Leeuwenhoek had engraved many years after, (PLATE IV.) +we shall find considerable difference, especially in the figures of +the dead animals, of a rabbit and in those of a dog, (which plate we +have also copied for the satisfaction of our readers) from all which +we may conclude, that Leeuwenhoek has not always observed objects +entirely alive: that the moving bodies, which he looked upon as +animals, appeared to him under different forms; and that he has varied +in his assertions, with a view of making the species of men and animals +perfectly consistent; he has not only varied in the basis of these +experiments, but even in the manner of making them, for he expressly +says, that he always diluted the liquor with water, in order to +separate, and to give more motion to these animalcules: nevertheless, +in his letter to Lord Brouncker, he says, that having mingled an equal +quantity of rain water with the seminal liquor of a dog, in which he +had before perceived an infinity of living animalcules, yet the mixing +of this water killed them. The first experiment of Leeuwenhoek's +therefore was made, like mine, without any mixture; and it even seems, +that he was not of opinion to mix any water with the liquor till a +long time after; because he thought he had discovered, by his first +essay, that water caused the death of the animalculę; which however is +not the fact. I think that the mixture of the water only dissolves the +filaments very suddenly; for I have seen but very few filaments in all +the experiments I have made after mixing the water with the seminal +liquor. + +As soon as Leeuwenhoek was persuaded that spermatic animals were +transformed into men, and other animals, he imagined he saw two sorts +in the seminal liquor of every animal, the one male, and the other +female; and this difference, according to him, served not only for the +generation of themselves, but for the production of males and females, +which was very difficult to conceive by a simple transformation. He +speaks of the male and female animalcule, in his letter printed in the +Philosophical Transactions, No. 145, and in many parts of his works,[U] +but he does not describe the difference of these male and female +animalcules, and which in fact never existed but in his own imagination. + +[U] See vol I. page 163, and vol. III. page 101, of his works. + +The famous Boerhaave having asked Leeuwenhoek, if he had not observed +in spermatic animals different degrees of growth and size? Leeuwenhoek +answered, that having dissected a rabbit, he observed in the semen an +infinite number of living animals. "Incredibilem, says he, viventium +animalculorum, numerum conspexerunt, cum hęc animalcula scypho +imposita vitreo & illic emortua, in rariores ordines disparassent, & +per continuos aliquot dies sępius visu examinassem, quędam ad justam +magnitudinem nondum excrevisse adverti. Ad hęc quasdam observavi +particulas perexiles & oblongas, alias aliis majores, &, quantum oculis +apparebat, cauda destitutas; quas quidem particulas non nisi animalcula +esse credidi, quę ad justam magnitudinem non excrevissent."[V] +Here then are animalcules of different sizes, some with tails and +others without, which much better agrees with my experiments, than +with Leeuwenhoek's own system. We differ only in one particular; he +says, that those without tails were young animalculę, which were not +arrived at their full growth; while I, on the contrary, have seen +these pretended animals quit the filaments with tails or threads, and +afterwards lose them by degrees. + +[V] See vol. IV. pages 280 and 281. + +In the same letter to Boerhaave, he says, in the semen of a ram, he +perceived animalcules following each other in swarms like a flock of +sheep. "A tribus circiter annis testes arietis, adhuc calentes, ad ędes +meas deferri curaveram, cum igitur materiam ex epididymibus eductam, +ope microscopii contemplarer, non sine ingenti voluptate advertebam +animalcula omnia, quotquot innatabant semini masculino, eundem +natando cursum tenere, ita nimirum ut quo itinere priora prinatarent +eodem posteriora subsequerentur, adeo ut hisce animalculis quasis +sit ingenitum, quod oves factitare vidimus, scilicet ut precedentium +vestigiis grex universus incedat." This observation, which Leeuwenhoek +made in 1713, and which he looks upon as singular and novel, proves +to me, that he had never examined the seminal liquors of animals with +attention, at least sufficient to give very exact descriptions of them. +Leeuwenhoek was sixty-one years old in 1713, had made microscopical +observations for more than forty-five years, had published the +discovery of spermatic animals for about thirty-six years, and then, +for the first time, saw in the seminal liquor of a ram, what is seen in +all seminal liquors, and what I have described in Experiment IX. in the +seed of a man; Experiment XII. in the seed of a dog; and in Experiment +XXIX. in that of a bitch. It is not necessary to suppose the spermatic +animals of the ram are endowed with instinct, to explain the floating +of these animals, in flocks like sheep, since those of a man, dog, or +bitch, does the same; and which motion depends solely on particular +circumstances, whose principle is, that all the fluid matter of the +seed is on one side, while the thick matter is on the other; for then +all the bodies in motion will be disengaged from the mucilage, and +follow the same road into the most fluid part of the liquor. + +In another letter, written the same year, to Boerhaave, he relates some +further observations he made on rams, and says, that he has seen, in +the _vasa deferentia_, flocks of animals which float all on one side, +and others which go in a contrary direction; and he adds, "Neque illud +in unica epididymum parte, sed & in aliis quas pręcideram partibus, +observavi. Ad hęc, in quadam parastatarum resecta portione complura +vidi animalcula, quę necdum in justam magnitudinem adoleverant, nam +et corpuscula illis exiliora & caudę triplo breviores erant quam +adultis. Ad hęc, caudas non habebant desinentes in mucronem, quales +tamen adultis esse passim comperio. Pręterea in quandam parastatarum +portionem incidi, animalculis quantum discernere potui, destitutam, +tantum illi quędam perexiguę inerant particulę, partim longiores, +partim breviores, sed altera sui extremitate crassiunculę; istas +particulas in animalcula transituras esse non dubitabam." It is easy +to see, by this passage, that Leeuwenhoek had seen, in this seminal +liquor, what I found in all; that is to say, moving bodies of different +sizes, figures, and motions; and which agrees much better with the idea +of organic particles in motion than of that with real animals. + +It appears, therefore, that Leeuwenhoek's observations are not contrary +to mine, although he has drawn very different conclusions from them. I +am persuaded that if any person would take the trouble of making the +like experiments they would not have any difficulty in discovering from +whence these differences proceed, and would find that I have advanced +nothing which is not conformable to truth; and to enable the reader to +decide thereon, I shall subjoin a few remarks. + +The filaments I have spoken of are not always to be perceived in the +seminal liquor of a man. To discover them it must be examined the +moment it is taken from the body, and even then it will sometimes +happen that there is not one to be seen. Sometimes the seminal liquor +presents, especially when it is very thick, only large globules, which +may be even distinguished with a common lens. By inspecting them with +the microscope they appear like young oranges; they are very opaque, +and a single one often fills up the whole table of the microscope. +The first time I saw these globules I thought they were some foreign +matters fallen into the liquor, but having examined different drops +I discovered that the whole was composed of these thick globules. I +selected one of the roundest, and whose size was such that, its centre +being in the middle of the table of the microscope, I could at the +same time observe the whole circumference; at first it was absolutely +opaque; a short time afterwards I perceived a bright luminous ring +to form on its surface, which remained about half an hour, and then +approached by degrees towards the centre, which became clear, and of +different colours, while the remainder of the globule continued opaque. +This light, which brightened in the centre of the globule, resembled +those seen in the great air bubbles. The globule then began to get +a little flat, and acquire a small degree of transparency. Having +examined it more than three hours I perceived no more alteration, +nor any appearance of motion, either internally or externally. I +then imagined, that by mixing this liquor with water, these globules +might be changed; in fact they did change, but they presented only a +transparent and homogeneous liquor, wherein was nothing remarkable. I +suffered the seminal liquor to liquefy of itself, and examined it at +the end of six, twelve, and twenty-four hours, but saw nothing more +than a fluid; without the smallest resemblance of life or motion. I +only relate this observation to shew that there are times when the +common phenomena are not to be seen in the seminal liquor. + +At times all the moving bodies appear to have tails, especially in +the semen of a man and a dog; the motion is then the least brisk, and +performed with difficulty. If this liquor is suffered to dry, the tails +or threads are deprived of motion the first; the anterior extremity +continues to vibrate for some time, and then all motion entirely +ceases. These substances may be preserved in this state of dryness for +a long time: if a small drop of water is mixed therewith, their figure +changes, they are reduced into many globules, which sometimes appear to +be in motion, as well by their approximation to each other, as by the +trepidation and twirling round their centres. + +These moving bodies in the seminal liquor of a man, dog, or bitch, so +nearly resemble each other, as to admit of mistaking one for the other, +especially if they are examined the moment the liquor is drawn from +the animal. Those of the rabbit appear smaller and brisker; but these +differences proceed more from the different states in which the liquor +is at the time of observation, than from the nature of the liquor +itself, which ought to be different in different kinds of animals; +for example, in that of a man I have seen streaks of thick filaments, +(_fig. 3._) and have perceived the moving bodies separate themselves +from these filaments from whence they appeared to proceed; but I have +never seen any thing like it in the semen of a dog; where, instead +of filaments, or separated streaks, it is commonly a mucilage whose +texture is more compact, and in which we with difficulty discern any +filamentary parts; yet this mucilage gives birth to moving bodies like +those in the semen of men. + +The motions of these bodies remain a longer time in the liquor of a +dog, than in that of a man; from which it is more easy to be certain of +the alteration of form above mentioned. The moment the liquor issues +from the body of the animal we perceive the animalcules to have tails; +in twelve, twenty-four, or thirty-six hours after, we shall find they +have lost those tails, and are then no more than ovals in motion, often +much brisker than at first. + +The moving bodies are always a little below the surface of the liquor. +On the surface some large transparent air bubbles, which have no +motion, generally appear, though sometimes these bubbles stir and +seem to have a progressive motion, but which is nothing more than the +agitation of the air. Below the moving substances we often see others +much smaller, and which only appear like globules, having no tails, +but the greatest number of which are oftentimes in motion. I have +also generally remarked, that in the infinite number of globules, in +all those liquors, those which are very small, are commonly black, or +darker than the rest; and that those which are extremely minute and +transparent, have but little or no motion; they appear also to weigh +specifically heavier, for they are always the deepest in the liquor. + + + + +CHAPTER XIII. + +REFLECTIONS ON THE PRECEDING EXPERIMENTS. + + +By the experiments we have just described, I was assured that females, +as well as males, have a seminal liquor which contains moving +substances; that these substances were not real animals, but only +living organic particles; and that those particles exist, not only in +the seminal liquors of the two sexes, but even in the flesh of animals, +and in the germs of vegetables. To discover whether all the parts of +animals, and all the germs of vegetables, contained living organic +particles, I caused infusions of the flesh of different animals to +be made, and of more than twenty kinds of seeds of different plants; +and after they had infused four or five days, in phials closely stopt +up, I had the satisfaction to see moving organic parts in them all; +some appeared sooner, and others later; some preserved their motion +for months together, while others were soon deprived of it; some +directly produced large moving globules, that had the appearance of +real animals, which changed their figures, separated, and became +successively smaller: others produced only small globules, whose +motions were very brisk; others produced filaments which lengthened +and seemed to vegetate, swelled, and afterwards thousands of moving +globules issued therefrom; but it is useless to detail my observations +on the infusion of plants, since Mr. Needham has published so excellent +a treatise on the subject. I read the preceding treatise to that able +naturalist, and often reasoned with him on the subject, particularly +on the probability that the germs of vegetables contained similar +moving bodies to those in the seed of male and female animals. He +thought those views sufficiently founded to deserve to be pursued; and +therefore began to make experiments on all parts of vegetables; and I +must own that the ideas I gave him on this subject have reaped greater +profit under his hands than they would have done from me. I could quote +many examples, but shall confine myself to one, because I indicated the +circumstance I am going to relate. + +To determine whether the moving substances seen in the infusions +of flesh were true animals, or only, as I supposed, moving organic +particles, Mr. Needham imagined that he had only to examine some +roasted meat, because if they were animals the fire must destroy +them; and if not animals, they might still be found there as well as +when the meat was raw; having therefore taken the jelly of veal, and +other roasted meat, he infused them for several days in water, closely +corked up in phials, and upon examination he found in every one of +them a great quantity of moving substances. He shewed me some of these +infusions, and among the rest that of the jelly of veal, in which there +were moving substances, perfectly like those in the seminal liquor of +a man, a dog, and a bitch, when they have no threads, or tails; and +although we perceived them to change their figures, their motions so +perfectly resembled those of an animal which swims, that whoever saw +them, without being acquainted with what has been already mentioned, +might certainly have taken them for real animals. I shall only add, +that Mr. Needham assured himself, by a multiplicity of experiments, +that all parts of vegetables contain moving organic particles, which +confirms what I have said, and extends my theory on the composition of +organized beings, and their reproduction. + +All animals, both male and female, and all vegetables whatsoever, it is +therefore evident are composed of living organic parts. These organic +parts are in the greatest abundance in the seminal liquor of animals, +and in seeds of vegetables. It is from the union of these organic +parts returned from all parts of the animal or vegetable body, that +reproduction is performed, and is always like the animal or vegetable +in which it operates; because the union of these organic parts cannot +be made but by the means of an internal mould, in which the form of +an animal or vegetable is produced. It is in this also the essence of +the unity and continuity of the species consists, and will so continue +while the great Creator permits their existence. + +But before I draw general conclusions from the system I am +establishing, I must endeavour to remove some objections which might be +made, and mention some other circumstances which will serve to place +this matter in a better light. + +It will be asked, why I deny those moving substances in the seminal +liquors to be animals, since they have constantly been regarded as +such by Leeuwenhoek, and every other naturalist, who has examined +them? I may also be told, that living organic particles are not +perfectly intelligible, if they are to be looked upon as animalculę; +and to suppose an animal is composed of a number of small animals, +is nearly the same as saying that an organized being is composed of +living organic particles. I shall therefore endeavour to answer these +objections in a satisfactory manner. + +It is certain that almost all naturalists agree in looking on the +moving substances in seminal liquors as real animals; but it is no less +certain, from my own observations, and those of Mr. Needham, on the +seed of the calmar, that these moving substances are more simple and +less organized beings than animals. + +The word _animal_, in the acceptation we commonly receive it, +represents a general idea formed of particular ideas drawn from +particular animals. All general ideas include many different ones, +which approach, or are more or less distant from each other, and +consequently no general idea can either be exact or precise. The +general idea which we form of an animal may be taken principally from +the particular idea of a dog, a horse, and other beasts, which appear +to us to act and move according to the impulse of their will, and which +are besides composed of flesh and blood, seek after their food, have +sexes, and the faculty of reproduction. The general idea, therefore, +expressed by the word _animal_, must comprehend a number of particular +ideas, not one of which constitutes the essence of the general idea, +for there are animals which appear to have no reason, will, progressive +motion, flesh nor blood, and which only appear to be a congealed +substance: there are some which cannot seek their food, but only +receive it from the element they live in: there are some which have no +sensation, not even that of feeling, at least in any sensible degree: +there are some have no sexes, or are both in one; there only belongs, +therefore, to the animal a general idea of what is common also to the +vegetable, that is, the faculty of reproduction. + +The general idea then is formed from the whole taken together, which +whole being composed of different parts, there is consequently between +these parts degrees and links. An insect, in this sense, is something +less of an animal than a dog; an oyster still less than an insect; a +sea-nettle, or a fresh-water polypus, still less than an oyster; and +as nature acts by insensible links, we may find beings which are still +less animated than a sea-nettle, or a polypus. Our general ideas are +only artificial methods to collect a quantity of objects in the same +point of view; and they have, like the artificial methods we shall +speak of, the defect of never being able to comprehend the whole. +They are likewise opposite to the walk of nature, which is uniform, +insensible, and always particular, insomuch that by our endeavouring to +comprehend too great a number of particular ideas in one single word, +we have no longer a clear idea of what that word conveys; because, the +word being received, we imagine that it is a line drawn between the +productions of nature; that all above this line is _animal_, and all +below it _vegetable_; another word, as general as the first, and which +is used as a line of separation between organized bodies and inanimate +matter. But as we have already said, these lines of separation do +not exist in nature; there are beings which are neither animals, +vegetables, nor minerals, and which we in vain might attempt to arrange +with either. For example, when Mr. Trembly first observed the polypus, +he employed a considerable time before he could determine whether it +was an animal or a plant; and possibly from this reason that it is +perhaps neither one nor the other, and all that can be said is, that it +approaches nearest to an animal; and as we suppose every living thing +must be either an animal or a plant, we do not credit the existence of +an organized being, that cannot be referred to one of those general +names; whereas there must, and in fact are, a great number of organized +beings which are neither the one nor the other. The moving substances +perceived in seminal liquors, in infusions of the flesh of animals, in +seed, and other parts of plants, are all of this kind. We cannot call +these animals, nor can we say they are vegetables, and certainly we can +still less assert they are minerals. + +We can therefore affirm, without fear of advancing too much, that the +grand division of nature's productions into _Animals_, _Vegetables_, +and _Minerals_, do not contain every material being; since there are +some that exist which cannot be classed in this division. We have +already observed, that nature passes by insensible links from the +animal to the vegetable, but from the vegetable to the mineral the +passage is quick, and the distance considerable; from whence the law of +nature's passing by imperceptible degrees appears untrue. This made me +suppose that by examining nature closely we shall discover intermediate +organized beings, which without having the power of reproduction, like +animals and vegetables, would nevertheless have a kind of life and +motion; other beings which, without being either vegetables or animals, +might possibly enter into the composition of both, and likewise other +beings which would be only the assemblage of the organic molecules I +have spoken of in the preceding chapters. + +In the first class of these kind of beings eggs must be placed; those +of hens, and other birds, are fastened to a common pedicle, and draw +their nourishment and growth from the body of the animal, but when +fastened to the ovary, they are not then real eggs, but only yellow +globules which separate from the ovary as soon as they have attained a +certain growth. Their internal organization is such that they derive +nourishment from the lymph, the matrix of the hen, and by which they +form the white membranes, and at last the shell. The egg therefore has +a kind of life and organization, a growth, expansion, and a form which +it assumes by its own powers. It does not live like an animal, nor +vegetate like a plant, nor is possessed of the power of reproduction; +nevertheless it grows, acts externally, and is organized. Must we not +then look upon it as a being of a separate class, and which ought not +to be ranked either with animal or mineral? for if it is pretended that +the egg is only an animal production, destined for the nutriment of +the chicken, and should be looked upon as a part of the hen; I answer, +that the eggs, whether impregnated or not, will be always organized +after the same mode: that impregnation only changes an almost invisible +part; and that it attains its perfection and growth, as well externally +as internally, whether it contains the chicken or not, and that +consequently it ought to be considered as a separate being. + +What I have said will appear more clear, if we consider the formation +and growth of the eggs of fish; when the female deposits them in the +water they are only the outlines of eggs, which being separated from +the body of the animal, attract and appropriate to themselves the +particles which agree the best for their nourishment, and grow thus +by intussusception. In the same manner as the hen's egg acquires the +white and membranes in the matrix, wherein it floats, so the eggs of +fish acquire their membranes and white in the water; and whether the +male impregnates them, by emitting on these the liquor of its roe, or +whether they remain unimpregnated, they do not the less attain their +entire perfection. It appears to me, therefore, that the eggs should +be considered as organized bodies, which being neither animals nor +vegetables, are a genus apart. + +A second class of beings, of the same kind, are the organized bodies +found in the semen of all animals, and which, like those in the milt of +a calmar, are rather natural machines than animals. These are properly +the first assemblages which result from the organic molecules we have +so much spoken of, and they are, perhaps, the parts which constitute +the organized bodies of animals. They are found in the semen of all +animals, because the semen is only the residue of the organic molecules +that the animal takes in with its aliment, and which, as we have +already observed, are those parts most analogous to the animal itself, +and most organic; it is those particles which compose the matter of the +semen, and consequently we must not be astonished to find organized +bodies therein. + +To be perfectly convinced that these organized bodies are not real +animals, we need only reflect on the preceding experiments. The moving +bodies in the seminal liquor have been taken for animals, because they +have a progressive motion, and are thought to have a tail; but if we +consider, on one hand, the nature of this progressive motion, which +finishes in a very short time without ever renewing its motion; and +on the other, the nature of these tails, which are only threads which +the moving bodies draw after them, we shall begin to hesitate; for an +animal goes sometimes slow, sometimes fast, and sometimes remains in +a state of rest; these moving bodies, on the contrary, always continue +the same motion, and I have never seen them stop and renew their +movement again. I ask, whether this kind of continued motion, without +any rest, is common to animals, and if that ought not to make us doubt +these moving bodies being real animals? An animal of any kind must also +have a constant form and distinct limbs; but these moving bodies vary, +and change their forms every moment, have no distinct limbs, and their +tails appear as a part which does not belong to the individual. Can +we then imagine these bodies to be real animals? In seminal liquors +filaments are seen which lengthen and appear to vegetate; after which +they swell and produce moving bodies. These filaments may be kinds +of vegetables, but the moving bodies which spring from them cannot +be animals, for a vegetable has never yet been seen to produce an +animal. These moving bodies are found in all vegetable and animal +substances; they are not produced by the modes of generation, they +have no uniformity of species, and therefore can neither be animals +nor vegetables. They are to be met with in the flesh of animals, and +in the substance of vegetables, but are most numerous in their seeds; +is it not therefore natural to regard them as living organic particles +which compose the animal or vegetable; as particles which having motion +and a kind of life, ought, by their union, to produce moving and living +beings, and so form animals and vegetables? + +But in order to leave this matter as little in doubt as possible, +let us examine other substances. Can it be said, the active machines +which Mr. Needham perceived in the milt of the calmar were animals? +Can it be thought that eggs, which are active machines of another +kind, are also animals? If we turn our eyes to the representation of +almost all the moving bodies Leeuwenhoek saw in different matters, +shall we not be convinced, even at the first inspection, that those +bodies are not animals, since not one of them has any limbs, but +are all either globular or oval? If we afterwards examine what this +celebrated naturalist says, when he describes the motion of these +pretended animals, we can no longer doubt of his being in an error +when he considered them as such; and we shall be still more and more +confirmed that they are only moving organic particles by the following +examples: Leeuwenhoek gives[W] the figure of the moving bodies which he +observed in the liquor of a male frog. This figure only represents a +slender body, long, and pointed at one of its extremities; and of this +he says, "Uno tempore caput (thus he calls the thickest extremity of +this moving body) crassius mihi apparebat alio; plerumque agnoscebam +animalculum haud ulterius quam a capite ad medium corpus, ob caudę +tenuitatem, & cum idem animalculum paulo vehementius moveretur (quod +tamen tarde fiebat) quasi volumine quodam circa caput ferebatur. Corpus +fere carebat motu; cauda tamen in tres quatuorve flexus volvebatur." +This then is the change of form which I mentioned to have seen, the +mucilage from which the moving bodies use all their efforts to be +disengaged, the slowness of their motion before they are disengaged; +and the animal, according to Leeuwenhoek, one part of which is +in motion, and the other dead: for he afterwards says, "Movebant +posteriorem solum partem, quę ultima, morti vicinia esse judicabam." +All this does not agree with an animal, but with what I have spoken +of; excepting that I never saw the tail move but by the agitation +of the body. He afterwards says, speaking of the seminal liquor of a +cod, "Non est putandum omnia animalcula in semine aselli contenta uno +eodemque tempore vivere, sed illa potius tantum vivere quę exitui seu +partui viciniora sunt, quę & copiosiori humido innatant prę reliquis +vita carentibus, adhuc in crassa materia, quam humor eorum efficit, +jacentibus." + +[W] Vol. I. p. 51. + +If these are animals, why have they not all life? why are they in the +most fluid part of the liquor alive, while those in the thickest are +not so? Leeawenhoek did not perceive that the thick matter, the origin +of which he attributes to the humour of the animalculę, is nothing but +a mucilaginous matter which produces them. By diluting this mucilage +with water, he would have given life to the whole of them. Even this +mucilage is oftentimes only a mass of those bodies which are set +in motion on being separated; and consequently this thick matter, +instead of being a humour, produced by the animalcules, is only the +substance of the animals themselves, or rather, as we have already +observed, the matter from which they originate. Speaking of the seed +of a cock, Leeuwenhoek says, in his letter to Grew, "Contemplando +materiam (seminalem) animadverti ibidem tantam abundantiam viventium +animalium, ut ea stuperem; forma seu externa figura sua nostrates +anguillas fluviatiles referebant, vehementissima agitatione movebantur; +quibus tamen substrati videbantur multi & admodum exiles globuli, item +multę plan-ovales figurę, quibus etiam vita posset attribui, & quidem +propter earundem commotiones; sed existimabam omnes hasce commotiones +& agitationes pro venire ab animalcules, sicque etiam res se habebat; +attamen ego non opinione solum, sed etiam ad veritatem mihi persuadeo +has particulas planam & ovalem figuram habentes, esse quędam animalcula +inter se ordine suo disposita & mixta vitaque adhuc carentia." Here +we see in the same seminal liquor animalcules of different forms; +and I am convinced, by my own experiments, that if Leeuwenhoek had +closely observed these oval substances, he would have discovered that +they moved by their own powers, and that consequently they were as +much alive as the rest. This change perfectly coincides with what +I have said, that they are organic particles which take different +forms, and not constant species of animals; for in the present case, +if the bodies, which have the figure of an eel, are true spermatic +animalcules, each, destined to become a cock, which supposes a very +perfect organization, and a very constant form, what will those be +which have an oval figure, and what end do they answer? He says indeed +afterwards, that these ovals maybe conceived to be the same animals, +by supposing their bodies to be twisted in a spiral form; but then +how shall we conceive that an animal, whose body is constrained, can +move without being extended? I maintain, therefore, that these oval +substances are no other than the organic particles separated from their +threads, and that the eels were the separated parts which dragged those +threads after them, as I have many times perceived in other seminal +liquors. + +Leeuwenhoek, who imagined all these moving bodies were animals, and +established a system thereon; who also pretended, that spermatic +animals must become men and animals, now suspected they were only +natural machines, or organic particles in motion; for he does not doubt +these spermatic animals contained the great animal in miniature, he +says, "Progeneratio animalis ex animalculo in seminibus masculinis +omni exceptione major est; nam etiamsi in animalculo ex semine masculo +unde ortum est, figuram animalis conspicere nequeamus, attamen satis +superque certi esse possumus figuram animalis ex qua animal ortum est, +in animalculo quod in semine masculo reperitur, conclusam jacere sive +esse; & quanquam mihi sępius conspectis animalculis in semine masculo +animalis, imaginatus fuerim me posse dicere, en ibi caput, en ibi +humeros, en ibi femora; attamen eum ne minima quidem certitudine de iis +judicium ferre potuerim, hujusque certi quid statuere supersedeo, donec +tale animal, cujus semina mascula tam magna erunt, ut in iis figuram +creaturę ex qua provenit, agnoscere queam, invenire secunda nobis +concedat fortuna." This fortunate chance, which Leeuwenhoek desires, +presented itself to Mr. Needham. Every part of the spermatic animals of +the calmar are easy to be seen without a microscope; but they are not +young calmars, as Leeuwenhoek thinks, nor even animated, although they +are in motion, but only machines which must be regarded as the first +produce of the union of organic particles. + +Although Leeuwenhoek had not such an opportunity of undeceiving +himself, he nevertheless had another phenomena which ought to have had +that effect; for example, he had remarked that the spermatic animals of +a dog often change their figures, especially when the liquor was on the +point of evaporating; that these pretended animals had a hole in the +head when they were dead, and that this hole did not appear when they +were alive; he had seen that the part which he looked upon as the head +was full and plump when it was alive, and flaccid and flat when dead. +All this ought to have led him to doubt whether these moving bodies +were real animals; and consider it as agreeing better with a machine, +which empties itself like that of the calmar, than with a moving animal. + +I have said that these moving bodies, these organic particles, do +not move like animals, nor have an interval of rest. Leeuwenhoek has +observed the same: "Quotiescunque, says he, animalcula in semine +masculo animalium fucrim contemplatus, attamen illa se unquam ad +quietem contulisse, me nunquam vidisse, mihi dicendum est, si modo +sat fluidę superesset materię in qua sese commode movere poterant; +et eadem in continuo manent motu, & tempore quo ipsis moriendum +appropinquante, motus magis magisque deficit, usquedum nullus prorsus +motus in illis agnoscendus sit." It appears difficult to conceive that +animals can exist, from the moment of their birth till that of their +death, in a continual rapid motion without the least interval of rest; +and I cannot possibly imagine how these animals in the semen of a dog, +which Leeuwenhoek saw the seventh day in as rapid motion as they were +when they were first taken from the body of the animal, preserved +a motion during that time so exceedingly swift, that no animal has +sufficient power to move in for an hour; especially if we consider the +resistance which proceeds from the density and the tenacity of the +liquor. This kind of continued motion, on the contrary, agrees with +the organic particles, which, like artificial machines, produce their +effects in a continual operation, and which stop when that effect is +over. + +Among the great number of Leeuwenhoek's experiments, he, without +doubt, often perceived spermatic animals without tails; and he +endeavours to explain this phenomena by a supposition; for example, +he says, speaking of the semen of a cod, "Ubi vero ad lactum accederem +observationem, in iis partibus quas animalcula esse censebam neque +vitam neque caudam dignoscere potui; cujus rei rationem esse +existimabam, quod quamdiu animalcula natando loca sua perfecte mutare +non possunt tam diu etiam cauda concinne circa corpus maneat ordinata, +quodque ideo singula animalcula rotundum repręsentent corpusculorum." + +It would have been better to have said, as it in fact is, that the +spermatic animals of these fish have tails at certain times and none +at others, than to suppose their tails twisted so exactly round their +bodies as to give them the shape of a globule. But this must not lead +us to think that Leeuwenhoek only attended to the moving bodies which +he saw with tails, but rather that he did not describe the others, +because, although they were in motion, he did not regard them as +animals; and this is the cause that all the spermatic animals he has +depicted resemble each other, and drawn with tails, since he only +took them for real animals in that state; and that when he saw them +under other forms, he thought them imperfect, or rather that they +were dead. On the whole it appears, by my experiments, that far from +displaying their tails the more as they are in a more perfect condition +of swimming, as Leeuwenhoek says, they, on the contrary, lose their +tails in a gradual manner, till at last these tails, which are no more +than foreign bodies of the animalcules, and which they drag after them, +entirely disappear. + +In another part Leeuwenhoek, speaking of the spermatic animals of man, +says, "Aliquando etiam animadverti inter animalcula particulas quasdam +minores & subrotundas; cum vero se ea aliquoties eo modo oculis meis +exhibuerint, ut mihi imaginarer eas exiguis instructas esse caudis, +cogitare coepi annon hę forte particulę forent animalcula recens +nata; certum enim mihi est ea etiam animalcula per generationem +provenire, vel ex mole minuscula ad adultam procedere quantitatem: & +quis sit annoa ea animalcula, ubi moriuntur, aliorum animalculorum +nutritioni atque augmini inserviant?" By this passage it appears that +Leeuwenhoek had seen animals without tails in the seminal liquor of +a man, and that he is obliged to suppose them to be just born, and +not adult; but I have observed quite the contrary; for the moving +bodies are never larger than when they separate from the filaments, +and begin to move. When they are entirely disengaged from the mucilage +they become smaller, and continue decreasing as long as they remain +in motion. With respect to the generation of these animals, which +Leeuwenhoek speaks of as certain, I am persuaded no sign of generation +has ever been discovered; all he says is advanced on mere suppositions, +which it is easy to prove by his own observations; for example, he +says that the milt of certain fish, as the cod, fills by degrees with +seminal liquor, which after the fish has emitted, the milt dries up, +leaving only a membrane destitute of any liquor. "Eo tempore, says +he, quo ascellus major lactes suos emisit, rugę illę, seu tortiles +lactium partes, usque adeo contrahuntur, ut nihil pręter pelliculas +seu membranę esse videantur." How then does he understand that this +dry membrane, in which there is no longer either seminal liquor or +animalcules, can reproduce animals of the same kind the succeeding +year? if there was a regular generation in these animals, there could +not be this interruption, which in most fishes lasts for a whole year. +To draw himself out of this difficulty, he says, "Necessario statuendum +erit, ut ascellus major semen suum emiserit, in lactibus etiamnum +multum materię seminalis gignendis animalculis aptę remansisse, ex qua +materia plura oportet provenire animalcula seminalia quam anno proxime +elapso emissa fuerant." This supposition, that there remains something +in the seminal liquor in the milts to produce spermatic animals for +the succeeding year, is absolutely contrary to observations, for the +milt is in this interval only a thin and absolutely dry membrane. But +what reply can be made to a still further opposition to this point, +there being fish like the calmar, the seminal liquor of which is not +only renewed every year, but even the reservoir which contains it? Can +it be said, that there remains a seminal matter in the milt for the +production of the animals for the succeeding year, when even the milt +does not remain? it is therefore very certain that these pretended +spermatic animals are not multiplied, like other animals, by the mode +of generation; which alone is sufficient to make us presume, that those +particles which move in the seminal liquors are not real animals. Thus +Leeuwenhoek, who in the passage above quoted says, it is certain that +spermatic animals multiply and propagate by generation, nevertheless +owns, in another part, that the manner in which these animals are +produced is very obscure, and that he leaves to others the task of +clearing up this matter. "Persuadebam mihi," says he, speaking of the +spermatic animals of the dormouse, "hęcce animalcula ovibus prognasci, +quia diversa in orbem jacentia & in semet convoluta videbam; sed unde, +quęso, primam illorum originem derivabimus? in animo nostro concipiemus +horum animalculorum semen jam procreatum esse in ipsa generatione, +hocque semen tam diu in testiculis hominum hęrere, usquedum ad annum +ętatis decimum-quartum vel decimum-quintum aut sextum pervenerint, +eademque animalcula tum demum vita donari vel in justam staturam +excrevisse, illoque temporis articulo generandi maturitatem adesse! +sed hęc lampada aliis trado." I do not think it necessary to make any +remarks on what Leeuwenhoek says on this subject: he saw spermatic +animals without tails, and round, in the seed of a dormouse; "in semet +convoluta," says he, because he supposes that they should have tails, +and instead of being certain, as he before had been, that the animals +propagate by generation, he here seems convinced of the contrary. But +when he had observed the generation of pucerons, and was assured[X] +that they engendered without copulation, he caught the idea to explain +the generation of spermatic animals. "Quemadmodum, says he, animalcula +hęc quę pediculorum antea nomine designavimus (the pucerons) dum adhuc +in utero materno latent, jam prędita sunt materia seminali ex qua +ejusdem generis proditura sunt animalcula, pari ratione cogitare licet +animalculę in seminibus masculinis ex animalium testiculis non migrate +seu ejici quin post se relinquant minuta animalcula aut saltem materiam +seminalem ex qua iterum alia ejusdem generis animalcula proventura +sunt idque absque coitu; eadem ratione qua supradicta animalcula +generari observavimus." This supposition gives no more satisfaction +than the preceding: for we do not understand by this comparison of +the generation of these animalcules with that of a puceron, why they +are not found in the seminal liquor of a man, before he has attained +the age of fourteen or fifteen years; nor do we know from whence +they proceed, nor how they are renewed every year in fish, &c. and +it appears, that whatever efforts Leeuwenhoek made to establish the +generation of spermatic animals on some probability, it still remained +an entire obscurity, and would, perhaps, perpetually have remained so, +if the preceding experiments had not evinced that they are not animals, +but moving organic particles contained in the nutriment the animal +receives, and which are found in great numbers in the seminal liquor, +which is the most pure, and in the most organic extracts drawn from +this nutriment. + +[X] See vol. II. page 499, and vol. III. page 271. + +Leeuwenhoek acknowledges that he had not always found animalcules +in the seminal liquor of males; in that of the cock, for example, +which he had often examined, he saw spermatic animals in the form +of eels but once, and some years after he could not discover any +under that form, but observed some with large heads and tails, which +his designer could not perceive. He says also, that one season he +could not find living animals in the seminal liquor of the cod. All +these disappointments proceeded from his desire of finding tails to +these animals; and although he perceived little bodies in motion, he +did not consider them as animals, because they were without tails, +notwithstanding it is under that form they are generally seen, either +in seminal liquors, or infusions of animal or vegetable substances. He +says, in the same place, that he was never able to make his designer +perceive the spermatic animalcules of a cod, which he had so often +seen himself.--"Non solum, says he, ob eximiam eorum exilitatem, sed +etiam quod eorum corpora adeo essent fragilia, ut corpuscula passim +dirumperentur; unde factum fuit ut nonnisi rare, nec sine attentissima +observatione, animadverterem particulas planas atque ovorum in morem +longas, in quibus ex parte caudas dignoscere licebat; particulas +has oviformes existimavi animalcula esse dirupta, quod particulę hę +diruptę quadruplo fere viderentur majores corporibus animalculorum +vivorum." When an animal of any kind ceases to live, it does not then +suddenly alter its form, and from being long, like a thread, becomes +round like a ball; neither does it become four times larger after +its death than it was before. Nothing that Leeuwenhoek says here +agrees with the nature of animals; but, on the contrary, the whole +corresponds with a kind of machine, which, like those of a calmar, +empty themselves after having performed their functions. But let us +pursue this observation; he says, he has seen the spermatic animals +of the cod in different forms, "multa apparebant animalcula sphęram +pellucidam representantia;" he has also seen them of different sizes, +"hęc animalcula minori videbantur mole, quam ubi eadem antehac in tubo +vitreo rotundo examinaveram." + +There needs nothing more to shew that there are no constant and +uniform species of these animalcules; and that consequently they are +not animals, but only organic particles in motion, which, by their +different combinations, take different forms and sizes. These organic +moving particles are found in great quantities in the extract and +residue of our nutriment. The matter which adheres to the teeth, and +which in healthy people has the same smell as the seminal liquor, is +only a residue of the food, and a great number of these pretended +animals are also found there, some of which have tails, and resemble +those in the seminal liquor. Mr. Baker had four different kinds of +them engraved, and which were all of a cylindrical or oval make, or +globules with and without tails. I am persuaded, after having strictly +examined them, that not any of them are real animals, but are like +those in the seed, only living organical parts of the nutriment which +present themselves under different forms, Leeuwenhoek, who did not +know how to account for these pretended animals in the matter which +adhered to the teeth, supposed them to proceed from certain food they +were previously in, as cheese, &c. but we find them among the teeth of +those who do not eat cheese, as well as in those that do; besides, they +have not the least resemblance to mites, nor the other animalcules seen +in rotten cheese. In another place he says, these animals of the teeth +may proceed from the cistern water that is drank, because he observed +animals like them in dew and rain water, especially in that which +stagnates upon lead and tiles; but with which we can prove there is not +the least resemblance. + +Most seminal liquors dilute of themselves, and liquefy when exposed to +the air or a certain degree of cold; but they thicken when a moderate +degree of heat is communicated to them. I have exposed some of these +liquors to a very intense cold, as water on the point of freezing, but +it did no injury to these supposed animals; they continued to move with +the same swiftness, and as long as those which had not been so exposed, +but those which had suffered but a little warmth soon ceased to move, +because the liquor thickened. If the moving bodies were animals, +they were of a complexion and temperament quite different from all +others, to whom a gentle and moderate heat strengthens their powers and +motions, which the cold stops and destroys. + +Notwithstanding it may be thought I have dwelt too long upon this +subject, I cannot conclude it without making one remark, from which +some useful conclusions may be drawn. These pretended spermatic +animals, which are only living organic particles of the nutriment, not +only exist in the seminal liquors of the two sexes, and in the residue +of the nutriment which adheres to the teeth, but also in the chyle +and excrements. Leeuwenhoek having met with them in the excrements +of frogs, and other animals, which he dissected, was at first very +much surprised, and notable to conceive from whence these animals +proceeded, so entirely like those he had observed in the seminal +liquors, accuses himself of having, in dissecting the animal, opened +the seminal vessels, and that the seed had by that means been mixed +with the excrements. But having afterwards found them in the excrements +of other animals, and even in his own, he no longer knew to what to +attribute them. Leeuwenhoek, it is worthy remark, never met with +them in his own excrements, but when they were liquid. Every time he +was disordered and the stomach did not perform its functions, and was +relaxed, he discovered these animalcules; but when the concoction of +the food was well performed, and the excrement was hard, there was not +a single one, although it was diluted with water. This seems perfectly +to agree with all we have before advanced: for when the stomach and +intestines perform their functions, the excrements are only the grosser +parts of the nutriment; and all that is really nutritive and organic +passes into the vessels which serve to nourish the animal; whereas if +the stomach and intestines are not in a condition to comminute the +food, then it passes with the inanimate parts, and we find the living +organic molecules in the excrements; from whence it may be concluded, +that those which are often lax must have less seminal liquor, and be +less proper for generation, than those of a different habit of body. + +In all I have said, I constantly supposed the female furnished a +seminal liquor, which was as necessary to generation as that of the +male. I have endeavoured to establish in Chap. I. that every organized +body must contain living organic particles, and I have endeavoured to +prove Chap. II. and III. that nutrition and reproduction operates by +the same cause; that nutrition is made by the intimate penetration +of these organic particles through each part of the body, and that +reproduction operates by the superfluity of these same organic +particles collected together from all parts of the body and deposited +in proper reservoirs. I have explained in Chap. IV. how this theory +must be understood in the generation of man and animals which have +sexes. Females then being organized bodies like males, they must also +have some reservoirs for the superfluity of organic particles returned +from every part of their bodies. This superfluity cannot come there +through any other form than that of a liquor, since it is an extract of +all parts of the body; and this liquor is that to which I have given +the name of the female semen. + +This liquor is not, as Aristotle pretends, an infecund matter of +itself, which enters neither as matter nor form into the business +of generation, but as essentially prolific as that of the male, +containing characteristic parts of the feminine sex, which the female +alone can produce, the same as the male contains particles necessary +to form the masculine organs; and each of them contains every other +organic particle that can be looked on as common to both sexes; which +causes that, by their mixture, the daughter may resemble her father, +and the son his mother. This semen Hippocrates says, is composed of +two liquors; the one strong, for the production of males; and the +other weak, for the production of females. But this supposition is +too extended; I do not see how it is to be conceived that a liquor, +which is the extract of every part of the female body, should contain +particles for the formation of the male organs. + +This liquor must enter by some way into the matrix of animals which +bear and nourish their foetus within the body, and in others, as +oviparous animals, it must be absorbed by the eggs, which may be looked +upon as portable matrixes. Each of these matrixes contains a small +drop of this prolific liquor of the female, in the part that is called +the _cicatrice_. When there has been no communication with the male, +this prolific drop collects under the form of a small mole, or mass, +as Malpighius observes; but when impregnated by that of the male; it +produces a foetus which receives its nutriment from the juices of the +egg. + +Eggs, instead of being parts generally found in every female, are +therefore only instruments made use of by Nature to serve as the matrix +in females which are deprived of that organ. Instead also of being +active and essential to the first fecundation, they only serve as +passive and accidental parts for the nutrition of the foetus already +formed by the mixture of the liquor of the two sexes in a particular +part of this matrix. Instead also of being existing bodies, inclosed, +_ad infinitum_, one within the other, eggs, on the contrary, are bodies +formed from the superfluity of a more gross and less organic part of +the food, than that which produces the seminal and prolific liquor; and +are in oviparous females something equivalent, not only to the matrix, +but even to the menstrua in the viviparous. + +We should be perfectly convinced, that eggs are only destined by Nature +to serve as a matrix in animals who have not that viscera, by those +females producing eggs independant of the male. In the same manner as +the matrix exists in viviparous animals, as a part appertaining to the +female sex, hens, which have no matrix, have eggs in their room, which +are successively produced of themselves, and necessarily exist in the +female independently of any communication with the male. To pretend +that the foetus is pre-existing in the eggs, and that these eggs are +contained, _ad infinitum_, within each other, is nearly the same as +to pretend that the foetus, is pre-existing in the matrix, and that +the matrix of the first female inclosed all that ever were or will be +produced. + +Anatomists have taken the word _egg_ in several acceptations and +meanings. When Harvey took for his motto, _Omnia ex ovo_, he understood +by the word egg, as applied to viviparous animals, the membrane which +includes the foetus and all its appendages: he thought, he perceived +this egg, or membrane, form immediately after the copulation of the +male and the female. But this egg does not proceed from the ovium +of the female; and he has even maintained, that he did not remark +the least alteration in this testicle, &c. We perceive there is here +nothing like what is commonly understood by the word egg unless the +figure of the bag may be supposed to have some resemblance thereto. +Harvey, who dissected so many viviparous females, did not, he says, +ever perceive any alteration in the ovaria; he looked on them even +as small glands, perfectly useless to general ion,[Y] although they +undergo very remarkable changes and alterations in them, since we +may perceive in cows the glandular bodies grow from the size of a +millet seed to that of a cherry. This great anatomist was led into +this error by the smallness of the glandular bodies in the species +of deer, to which he principally paid his attention. C. Peyerus, who +also made many experiments on them, says, "Exigui quidem sunt damarum +testiculi, sed post coitum foecundum, in alterutro eorum, papilla, +sive tuberculum fibrosum, semper succrescit; scrofis autem pręgnantibus +tanta accidit testiculorum mutatio, ut mediocrem quoque attentionem +fugere nequeat."[Z] This author imagines, with some reason, that the +minuteness of the testicles of does, is the cause of Harvey's not +having remarked the alterations; but he is wrong in advancing that the +alterations he had remarked, and which had escaped Harvey's notice, did +not happen till after impregnation. + +[Y] See Harvey Exercit. 64 and 65. + +[Z] Vide Conradi Peyeri Merycologia. + +It appears that Harvey was deceived in many other essential points; +he asserts, that the seed of the male does not enter into the matrix +of the female, and even that it cannot; yet Verheyen found a great +quantity of the male seed in the matrix of a cow, which he dissected +six hours after copulation.[AA] The celebrated Ruysch asserts, that +having dissected a woman who had been caught in the act of adultery, +and was assassinated, he found, not only in the cavity of the matrix, +but also in the trunks, a quantity of the seminal liquor of the +male,[AB] Valisnieri affirms, that Fallopius and other anatomists +had also discovered male seed in the matrix of many women. After the +positive testimony of these great anatomists, there can remain no doubt +but Harvey was deceived in this important point; especially when to +these are added that of Leeuwenhoek, who found the male seed in the +matrix of a great number of females of different species. + +[AA] See Verheyen Sup. Anat. Tra. v. cap. iii. + +[AB] See Ruysch, Thes. Anat. p. 90, tab. VI, fig. I. + +Harvey makes another error in speaking of an abortion in the second +month, where the mass was as large as a pigeon's egg, but without any +foetus regularly formed; whereas, it is maintained by Ruysch, and +many other anatomists, that the foetus is perceptible, even to the +naked eye, in the first month. The History of the Academy mentions +a foetus, that was completely formed in twenty-one days after +impregnation. If to these authorities we add that of Malpighius, +who perceived the chicken in the cicatrice, immediately after the +egg was laid by the hen, we cannot doubt, but that the foetus is +formed immediately after copulation; consequently, we must not pay any +credit to what Harvey says on the parts increasing one after the other +by juxta-position, since they are all existent from the first, and +gradually expand until the whole is complete. + +De Graaf took the acceptation of the word egg in a quite different +light to Harvey: he insists that the testicles of women were true +ovaries, and contain eggs like those of oviparous, animals, only that +they are much smaller, do not quit the body, and are never detached +till after impregnation, when they descend from the ovary into the +horns of the matrix. The experiments of De Graaf have contributed most +to establish the existence of these pretended eggs, which yet is not at +all founded; for this famous anatomist is deceived, first, by mistaking +the vesicles of the ovarium for eggs, whereas they are inseparable from +it, form parts of its substance, and are filled with a kind of lymph. +Secondly, he is also deceived when he considers the glandular bodies +to be the covering of those eggs, or vesicles; for it is certain, +by Malpighius's, Valisnieri's, and my own observations, that the +glandular bodies neither surround nor contain one of those vesicles. +Thirdly, he is deceived still more when he supposes the glandular body +is never formed till after fecundation; as they are invariably found in +every female who has attained the age of puberty. Fourthly, he is no +less deceived when he believes that the globules which he saw in the +matrix, and which contained the foetuses, ware the same vesicles, +or eggs, which had fallen from the ovariam, and which, he remarks, +were become ten times smaller than they were in the ovary. This remark +alone, one would imagine, Should have made him perceive his error. +Fifthly, he is wrong in saying that the glandular bodies are only the +coverings of the fecundated eggs, and that the number of coverings, +or empty follicles, always answer to the number of foetuses. This +assertion is entirely contrary to truth: for on the testicles of all +females we find a greater number of glandular bodies, or cicatrices, +than there are productions of foetuses, and they are also found in +those which have never brought forth. To this we may add, that neither +he, Verheyen, nor any other person, have ever seen these eggs, much +less these pretended coverings, on which they have, notwithstanding, +established their system. + +Malpighius, who perceived the growth of the glandular bodies in the +female testicles, was deceived when he thought he had seen the egg in +their cavities, since they contain only liquor; nor indeed has anything +like an egg ever been discovered. + +Valisnieri, who was not deceived in facts, has yet drawn false +conclusions in asserting that, although neither himself, nor any +anatomist in whom he could confide, ever found the egg in the cavity of +the glandular body, yet it must there exist. + +Let us, therefore, examine what may be fairly called the real +discoveries of these naturalists. Graaf was the first who perceived +there were alterations in the female testicles; and he had reason +to affirm, they were parts essential and necessary to generation. +Malpighius demonstrated that these alterations were occasioned by the +glandular bodies which grew to perfect maturity, afterwards they become +flaccid, obliterated, and left only a slight cicatrice remaining. +Valisnieri has placed this discovery in a very clear light; he has +shewn that these glandular bodies are found in the testicles of every +female; that they are augmented considerably in the season of love, +that they increase at the expence of the lymphatic vesicles of the +testicles, and that at the time of their maturity they were hollow and +filled with liquor. This, then, is all that can be reduced to truth on +the subject of the pretended ovaries and eggs of viviparous animals. +What must we conclude therefrom? Two things appear very evident: the +one, that there does not exist any eggs in the female testicles; the +other, that there exists a liquor in the vesicles of the testicle, and +in the cavity of the glandular bodies. We have demonstrated by the +preceding experiments, that this last liquor is the true seed of the +female, since it contains, like that of the male, spermatic animals, or +rather organic moving particles. + +We must, therefore, now be assured, that females have, as well as +males, a seminal liquor. After all that has been advanced, we cannot +doubt but the seminal liquor is the superfluity of the organic +nutriment, which is sent back from all parts of the body into the +testicles and seminal vesicles of the males, and into the testicles +and glandular bodies of females. This liquor, which issues by the +nipple of the glandular bodies, continually sprinkles the horns of the +matrix, and may easily procure admission either by the suction of the +membrane of these horns, or by the little opening which is at the upper +extremity, and thus enter into the matrix; but in the supposition of +these pretended eggs, which were ten or twenty times larger than the +opening of the horns of the matrix, we cannot comprehend how they could +enter therein. + +The liquor emitted by females, when they are excited, and which, +according to de Graaf, issues from the neck of the matrix, and the +orifice of the urethra, may be a superabundant portion of the seminal +liquor which continually distills from the glandular bodies on the +trunks of the matrix. But, possibly, this liquor may be a secretion +of another kind, and perfectly useless in generation. To decide this +question observations with a microscope are requisite; but _all_ +experiments are not permitted even to philosophers. I can only say, +that I am inclined to believe that the same spermatic animals would +be met with in this liquor as in that of the glandular bodies. I can +quote an Italian doctor on this subject, who made this observation with +attention, and which is thus related by Valisnieri: "Aggiugne il lodato +fig. Bono d'avergli anco veduti (animali spermatici) in questa linfa o +siero, diro cosi voluttuoso, che nel tempore dell'amorosa zuffa scappa +dalle femine libidinose, senza che si potesse sospettare che fossero +di que' del maschio, &c." If this circumstance is true, as I do not +doubt, it is certain, that this liquor is the same as that found in +the glandular bodies, and that, consequently, it is the true seminal +liquor: and although anatomists have not discovered the communication +between the vacuities of de Graaf and the testicles, that does not +prevent it being once in the matrix, from issuing out by the vacuities +about the exterior orifice of the urethra. + +From hence we must conclude that the most abandoned women will be the +least fruitful, because they emit that liquor which ought to remain in +the matrix for the formation of the foetus. Thus we see why common +prostitutes seldom have children, and why women in hot countries, where +they have stronger desires than in the cold, are much less fertile; but +we shall have occasion to speak of this hereafter. + +It is natural to think that the seminal liquor of the male or female +would not be fertile but when it contains moving bodies; nevertheless +that is still a question, and I should be led to think, as there are +different states of this liquor, that in which these organic particles +are seen in motion is not absolutely necessary for the purpose of +generation. The Italian physician, above quoted, never perceived +spermatic animals in his semen till he had attained a middle age, +although he was father of several children before, and continued to +have them afterwards. + +These spermatic bodies, which move, may be looked upon as the first +assemblages of the organic molecules which proceed from every part of +the body; when a quantity of them collect they may be perceived with +the microscope; but if they collect only in small quantity the body +which they form will be too minute to be perceived, and in this case we +shall not be able to distinguish any in the seminal liquor. A very long +continuance of observations would be necessary to determine what can be +the cause of all the differences remarked in the states of this liquor. + +I can assert, from having often tried it, that by infusing the seminal +liquors in water closely corked, at the end of three or four days +an infinite multitude of moving bodies will be found, although the +seminal liquors had no motion on being first taken from the body of +the animal. Flesh, blood, chyle, urine, nay all animal or vegetable +substances, contain organic particles, which move at the end of some +days in an infusion of water; they appear to act and move nearly in the +same manner, and though produced from different bodies are perfectly +similar, without any of them having a power peculiar to themselves. +If these bodies must absolutely be termed animals, it must be allowed +they are so imperfect that they ought to be looked upon as the outlines +of them, or rather as bodies simply composed of particles the most +essential to the existence of an animal; for natural machines, such as +those found in the roe of a calmar, although they put themselves in +action at certain times, are certainly not animals, although they are +organized, acting, and, as I may say, living beings. + +If it is once allowed, that the productions of Nature follow in an +uniform order, and advance by imperceptible degrees and links, we shall +have no difficulty in conceiving there are organic bodies existing, +which belong neither to animals, vegetables, nor minerals. + +It is certain, however, that all animals and vegetables contain an +infinity of organic living molecules. These molecules successively +take different forms, and different degrees of motion and activity, +according to different circumstances They are in a much greater number +in the seminal liquor of both sexes, and in the germs of plants, than +in other parts of the animal or vegetable. There exists, then, a +living substance in animals and vegetables, common to both, and which +substance is necessary to their nutrition. An animal procures nutriment +from an animal or vegetable substance, and the vegetable can likewise +be nourished from an animal or vegetable in a decomposed state. This +nutritive substance, common to both, is always living, always active, +and produces an animal or vegetable, as it finds an internal mould or +an analogous matrix, as we have explained in the first chapters; but +when this active substance collects in great abundance, in those parts +where it can unite, it forms in the animal body other living creatures, +such as the tape-worm, ascarides, and worms, which are sometimes found +in the veins, in the sinus of the brain, in the liver, &c. These kinds +of animals do not owe their existence to the animals of the same +species, and we may, therefore, suppose, they are produced by this +organic matter when it is extravasated, or is too abundant for the +lacteal vessels to absorb. We shall hereafter have occasion to examine +more largely the nature of those worms, and many other animals which +are formed in a similar manner. + +When this organic matter, which may be looked on as an universal seed, +is collected in any great quantity, as in the seminal liquors, and in +the mucilaginous parts of the infusion of plants, its first effect is +to vegetate, or rather to produce vegetating beings. These zoophytes +swell, extend, ramify, and produce globules, ovals, and other small +bodies, of different figures, which have all a kind of animal life, a +progressive motion, which is often very swift, and sometimes very slow. +These globules themselves decompose, change their figures, and become +smaller; and in proportion as they diminish in size the rapidity of +their motion augments. + +I have sometimes thought that the venom of the viper, and other active +poisons, even that of the bite of a mad dog, might possibly be this +active matter too rarefied; but I have not as yet had time to make the +experiments which I had projected on this matter, as well as on drugs +used in medicine; all that I can at present ascertain is, that all +infusions of the most active drugs swarm with moving bodies, which form +therein in much less time than in other substances. + +Almost all microscopic animals are of the same nature as the organized +bodies which move in the seminal liquor, in the infusions of vegetables +and the flesh of animals; the eel-like bodies in flour, vinegar, and +water, in which lead has been soaked, are beings of the same nature as +the first, and have a like origin. + + + + +CHAPTER IX. + +VARIETIES IN THE GENERATION OF ANIMALS. + + +The matter which serves for the nutrition and reproduction of animals +and vegetables is therefore the same; it is a productive and universal +substance, composed of organic molecules, and whose union produces +organized bodies. Nature always works on the same fund, which is +inexhaustible, but the means she employs to stamp its value are +different, and these differences, or general agreements, deserve +attention, because it is from thence we must derive our reasons to +account for exceptions and particular varieties. + +In general large animals are less productive than small. The whale, +elephant, rhinoceros, camel, horse, the human species, &c. only +produce one, and very seldom two, at a birth; whereas small animals, +as rats, herrings, insects, &c. produce a great number at a time. Does +not this difference proceed from there being more food required to +support a large body than to nourish a small one, and from hence the +former has less superfluous organic particles, which would convert +into semen, than the latter? It is certain that small animals eat more +in proportion than large ones; but it is likewise probable that the +prodigious multiplication of the small animals, as bees, flies, and +other insects, may be attributed to their being endowed with very fine +and slender limbs and organs, by which they are in a condition to chuse +what is most substantial and organic in the vegetable or animal matters +from whence they derive their nutriment. A bee, who lives on the +purest parts of flowers, certainly receives more organic particles in +proportion than a horse who feeds on the grosser parts of vegetables, +hay, &c. The horse produces but one at one time, whereas the bee will +bring forth three thousand. + +Oviparous animals are in general smaller than the viviparous, and +produce also more at a birth. The duration of the foetus in the +matrix of viviparous animals likewise opposes their increase, nor can +there be any new generation take place during gestation, or while they +are suckling their young; whereas oviparous animals produce at the same +time both matrix and foetuses, which they cast out of the body, and +are therefore almost always in a state of reproduction; and it is well +known that by preventing a hen from setting, and largely feeding, the +number of her eggs will be considerably increased. If hens cease to +lay when they sit, it is because they have ceased to feed; and it is +the fear lest their eggs should not produce which causes them not to +quit their nests but once a day, and that for a very short time, during +which they take a little nutriment, but not one-tenth part of what they +take at other times. + +Animals which produce but a small number at a time, acquire the chief +part of their growth before they are fit for engendering, whereas those +which multiply numerously generate before they have received half their +growth. The human species, the horse, the ass, the goat, and the ram, +are not able to engender until they have obtained nearly the whole of +their growth. It is the same with pigeons and other birds, who lay but +a few eggs; but those which produce in great numbers, as poultry, fish, +&c. engender much sooner. A cock is capable of engendering at the age +of three months, when he has not attained a third part of his growth; +a fish, which at the end of twenty years will weigh thirty pounds, +engenders in the first or second year, when perhaps it does not weigh +half a pound. But exact observations on the growth and duration of +the life of fish are still wanting: their age may be nearly known by +examining the annual layers of their scales; but we are not certain how +far that may extend. I have seen carp in the Comte de Maurepas' canals, +at his castle at Pont Chartrain, which were said to be 150 years old, +and they appeared as brisk and lively as the common carp. I will not +say, with Leeuwenhoek, that fish are immortal, or at least can never +die with age; all must perish in time, that is; all which have a +beginning, a birth, must arrive to an end, or death; but fish, living +in an uniform element, and being sheltered from the vicissitudes and +all the injuries of the air, must live a longer time in the same state +than other animals, especially if these vicissitudes of the air be, as +a great philosopher asserts, the principal causes of the destruction of +living beings. But what must contribute to the long duration of their +life is, that their bones are softer than those of other animals, and +do not harden with age. The bones of fish lengthen, and grow thick +without taking any more solidity; whereas the bones of other animals +continually increase in hardness and density, until at length, being +absolutely full, the motion of their fluid ceases, and death ensues. In +their bones the repletion or obstruction, which is the cause of natural +death, is formed by such slow and insensible degrees, that fish must +require much time to arrive at what we call old age. + +All quadrupeds covered with hair are viviparous; all those covered +with scales oviparous. May we not then believe than in oviparous +quadrupeds, a much less waste is made by transpiration, than the +cloathing of scales retains; whereas in animals covered with hair +this transpiration is more free and abundant? and is it not partly +by this superabundance of nutriment, which cannot be carried off by +transpiration, that those animals multiply so abundantly, and are +enabled to go so long without food? All birds and all insects that fly +are oviparous, excepting some kinds of flies which bring forth their +young alive. These flies have no wings at their birth, but they shoot +out and grow by degrees, and which they cannot use before they are of +full growth. Scaly fish are likewise oviparous; as are all reptiles +which have no legs, such as snakes and different kinds of serpents; +they change their skins, which are composed of small scales. The viper +is only a slight exception to the general rule, for it is not truly +viviparous, as it produces eggs, from which the young are hatched; it +is certain this is performed in the body of the mother, who instead +of casting those eggs, like other oviparous animals, she retains and +hatches them in her own body. The salamander, in which eggs and young +ones are found at the same time, as observed by M. de Maupertuis, is +an exception of the same kind in oviparous quadrupeds. + +Most animals are perpetuated by copulation; yet many birds seem only +strongly to compress the females; indeed the ostrich, Crane, and +some few others, are so well supplied as to leave intromission no +ways equivocal. Male fish approach the female in the spawning time; +they seem even to rub their bellies against each other, for the male +often turns upon its back to meet the belly of the female; but the +necessary part for copulation does not exist in them; and the male +fish approaches the female only to emit the liquor in their milts on +the eggs, which the female then deposits; and it seems rather to be +attracted by the eggs than the female; for when she ceases throwing out +the eggs, he instantly forsakes her, and with eagerness pursues the +eggs, which the stream carries away, or that the wind disperses. Male +fish may be seen to pass and repass every spot where eggs are deposited +several times. It is certainly not for the love he bears the female +that all these motions are made, because it is not to be presumed he +always knows her; often being seen to emit his liquor on all eggs that +he comes near, and that often before he has met with the female to +which they belonged. + +There are therefore animals, distinguished by sexes, which have proper +parts for copulation, and some which are deficient in them; others, as +snails, have both, and the two sexes in the same individual; others, +as vine-fretters, have no sex, and engender in themselves separately; +although they couple together when they please, we cannot determine +whether that is a conjunction of sexes; if it is so, we must suppose +that Nature has included in this small individual more faculties for +generation than in any other kind of animal, and that it not only has +the power of reproducing distinctly, but also the means of multiplying +by the communication of another individual. + +But whatever difference takes place in generation, Nature, by a new +production, prepares the body for it, and which, whether manifested +outwardly, or concealed internally, always precedes generation. The +ovaries of oviparous animals, and the testicles of female viviparous +animals, before the season of impregnation, experience a considerable +change. Oviparous animals produce eggs, which at first are attached to +the ovaries, by degrees they increase in size, until they fall into +the canal of the matrix, where they acquire their white membranes, and +shell. This production has marks of the fecundity of the female, and +without which generation cannot be performed: so in viviparous females +there are always one or more glandular bodies on the testicles, which +by degrees grow under the membrane that surrounds them; these glandular +bodies enlarge and pierce, or rather impel and lift up the membrane of +the testicle; when their maturity is complete, a small slit or several +small holes appear at their extremities, by which the seminal liquor +escapes, and falls into the matrix: these glandular bodies are new +productions that precede generation, and without which there would not +be any. + +In males there is also a similar change which always precedes their +capacity for generating. In oviparous animals a great quantity of +liquor fills a considerable reservoir, and which reservoir itself is +sometimes formed every year; as in the calmar and some other fish. The +testicles of birds swell surprisingly just preceding their amorous +season. In viviparous males the testicles also swell considerably in +those who have seasons, and in general there is a swelling and an +extension of the genital members in all species, which, although it be +external, must be regarded as a new production necessarily preceding +generation. + +In the body of every animal, male or female, new productions are formed +which precede generation; and when there is no real production there +is always a swelling, and considerable extension in some of the parts. +There are species in which this new production is not only manifest, +but even the whole body seems to be renewed before generation can be +performed; as is the case with insects whose various metamorphoses +seem to be only for the purpose of generating; for the growth of the +animal is completed before it is transformed. It ceases from taking +nutriment, has no organs for generation, no means of converting the +nutritive particles, of which they abound, into eggs or seminal liquor, +and therefore this superfluity unites and moulds itself at first into +a form something like that of the original. The caterpillar becomes +a butterfly, because, for these reasons, it is unable to produce +small organized beings like itself; the organic particles, always +active, take another form, by uniting, whose figure answers in part, +and even in essential constitution, to that of the caterpillar, but +in which the organs of generation are developed, and may receive +and transmit the organic particles of the nutriment which forms the +eggs, and the individuals of the species. The individuals which +proceed from the butterfly ought not to be butterflies, because the +nutriment, from whence the organic particles proceed, was taken while +in the form of caterpillars; the produce therefore must be similar, +and not butterflies, which is only an occasional production of the +superabundant nutriment; a method adapted by Nature to accomplish the +purposes of generation in these species, as by the glandular bodies and +milts in other animals. + +When the superabundant quantity of organic nutriment is not great, +as in man and most large animals, generation is not made till the +growth of the animal is nearly complete, and then it is confined to +the production of a small number of individuals. When these particles +are more abundant, as in many kinds of birds, and in oviparous fishes, +generation is completed before the animal has received its full +growth, and their production of individuals is very numerous. When +the quantity of particles is still greater, as in insects, it first +forms a large organic body, which, though retaining the essential +constitution of its original, differs in many parts, as the butterfly +from the caterpillar, but shortly produces an astonishing number of +young, similar in form to the animal which selected the nutriment. When +the superabundance is greater still, and when at the same time the +animal has the necessary organs for generation, as the vine-fretter, it +immediately produces a generation in every individual, and afterwards +a transformation, like other insects. The vine-fretter becomes a fly, +but cannot produce any thing, because it is only the remainder of the +organized particles which had not been made use of in the production of +the young. + +Almost every animal except man has stated times for generation. Spring +is marked out for birds. Carp, and many kinds of fish, spawn in June +and August. Barbel, and other kinds, in spring. Cats have three +seasons, in January, May, and September. Roebucks, in December. Wolves +and Foxes, in January. Horses, in summer. Stags, in September and +October; and almost all insects generate in autumn: these last seem to +be totally exhausted by generation, and die a short time after. Other +animals, though not exhausted, become extremely lean and very weak, +and require a considerable time to repair the loss which is made of +the organic substance. Others are exhausted still less, and are soon +restored to an engendering state; while man is scarcely in the least +affected; his loss is speedily repaired, and therefore may be said to +be at all times in a state for propagation; all which depends solely +on the particular construction of the animal organs. The grand limits +Nature has placed in the mode of existence are equally conspicuous +in the manner of receiving and digesting the food, in the manner of +retaining it in, or excluding it from, the body, and in the means by +which the organic molecules, necessary for reproduction, are extracted. +In a word, we shall find throughout all nature, that all what can be, +is. + +The same difference exists in the time of female gestation; some, as +mares, carry their young eleven or twelve months; others, as women, +cows, &c. nine months; others, as foxes, wolves, &c. five months; +bitches, nine weeks; cats, six weeks; rabbits, thirty-one days. Most +birds come out of the egg at the end of twenty-one days; though some, +as canary birds, hatch in thirteen or fourteen days. The variety is +as great here as in every thing else relative to animals. The largest +animals which produce only few, are those which go the longest with +young; this still more confirms what we have already said, that the +quantity of organic food is in proportion less in large than in small +animals; for it is from the superfluity of the mother's food that the +foetus derives what is necessary to the growth and expansion of its +parts, and since this expansion demands much more time in large than +in small animals, it is a proof that the quantity of matter which +contributes is not so abundant in the first as in the last. + +There is, therefore, an infinite variety in animals, with respect to +the time and manner of gestation, engendering, and bringing forth; and +this variety is found even in the causes of generation; for although +the general principle of production is this organic matter common to +all that lives or vegetates, the manner in which the union is made, +must have infinite combinations, which must all proceed from the source +of new productions. My experiments clearly demonstrate, that there are +no pre-existing germs, and at the same time prove that the generation +of animals and vegetables is not equivocal; there are, perhaps, as +many beings, either living or vegetating, which are produced by the +fortuitous assemblage of organic molecules, as by a constant and +successive generation. It is to those productions we should apply +the axiom of the ancients, "Corruptio unius, generatio alterius." +The corruption and composition of animals and vegetables produce an +infinite number of organized bodies; some, as those of the calmar, form +only kinds of machines, which, although very simple, are exceedingly +active; others, as the spermatic animalcules, seem by their motion, to +imitate animals; others imitate vegetables by their manner of growing +or extending; there are others, as those of blighted corn, which may +be made to live and die alternately, and as often as we please; there +are still others, even in great quantities, which are at first kinds of +vegetables, afterwards become species of animals, then return again to +vegetables, and so on alternately. There is a great appearance, that +the more we shall observe this race of organized beings, the more we +shall discover varieties, always so much the more singular as they are +the more remote from our sight, and from the varieties of other animals +that have already become known to us. + +For example, spurred barley, which is produced by an alteration or +decomposition of the organic substance of the grain, is composed of +an infinity of little organized bodies, like to eels. By infusing +the grain for ten or twelve hours in water, we find them to have a +remarkable twirling, and a slight progressive motion; when almost dry, +they cease to move, but by adding fresh water their motion returns. +The same effects may be produced for months, or even years; insomuch +that we can make these little machines act as often and as long as we +please without destroying them, or their losing any of their power or +activity. Their threads will sometimes open, like the filaments of +semen, and produce moving globules; we may therefore suppose them to be +of the same nature, only more fixed and solid. + +Eels, in paste made with flour, have no other origin than the union of +the organic particles of the most essential parts of the grain: the +first which appear are certainly not produced by many others; yet, +although they have not been engendered, they engender others. By +cutting them with the point of a lancet, we may perceive small eels +come from their bodies in great numbers; the body of the animal appears +to be only a sheath or bag which contains a multitude of other little +animals, which perhaps are themselves only sheaths of the same kind, in +which the organic matter assimilates, and takes the form of eels. + +There requires a great number of observations to be made to establish +classes and races between such singular beings, which are at present so +little known; there are some which may be regarded as real zoophytes, +which vegetate, and at the same time appear to twirl and move like +animals. There are some that at first appear to be animals, which +afterwards join and form kinds of vegetables. A little attention to the +decomposition of a grain of wheat infused in water will elucidate all I +have asserted. I could add more examples, but I have related these only +to point out the varieties there are in generation. There are certainly +organized beings which we regard as animals, but which are not +engendered by others of the same kind; there are some which are only +a kind of machines, whose action is limited to a certain effect, and +which can act but once in such a certain time, as those in the calmar; +and there are others, as we have just remarked, which we can cause to +act as long and as often as we please. There are vegetating beings +which produce animated bodies, as the filaments of the human seed, +from whence the active globules spring, and which move by their own +powers. In the corruption, fermentation, or rather the decomposition +of animal and vegetable substances, there are organized bodies which +are real animals, and can propagate their like, although they have +not been so produced. The limits of these varieties are perhaps still +greater than we can imagine. We may extend our ideas, and exert every +effort to reduce the effects of Nature to certain points, and class her +productions to certain classes, yet an infinite number of links will +always escape us. + + + + +CHAPTER X. + +OF THE FORMATION OF THE FOETUS. + + +It appears to be clearly ascertained by the experiments of Verheyen, +who in one of them found the seed of a bull in the matrix of a cow; +and by those of Ruysch, Fallopius, Leeuwenhoek, and many others, who +perceived the male semen in the uterus of women, and numberless other +animals, that the seminal liquor of the male enters by some means +into the matrix of the female. It is probable, that in the time of +copulation the orifice of the matrix opens to receive the seminal +liquor, but if that is not the case, the active and prolific substance +of this liquor, may penetrate the membranes of the matrix; for the +seminal liquor being, as we have proved, almost all composed of organic +molecules, which are in great motion, and extremely minute, they may +pass across the coat of the closest membranes, and penetrate those of +the matrix with the greatest facility. + +What proves that the active part of this liquor may not only pass +through the pores of the matrix, but even penetrate its substance, is +the sudden change that immediately takes place after conception. The +menses are suppressed, the matrix becomes softer, swells, and appears +inflamed. All these alterations can only happen by the action of an +external cause; by the penetration of some part of the seminal liquor +into the substance even of the matrix. This penetration not only +operates on the external surface of the matrix, but on all the other +parts of which this viscera is composed, like that penetration by which +nutrition and expansion is produced. + +We shall be easily persuaded that it is so, when we consider that +the matrix, during the time of gestation, not only augments in bulk +but also in quantity of matter, and that it has a kind of life or +vegetation, which is continually increasing till the time of delivery; +for if the matrix was only a pouch, a destined receptacle to receive +the seed and contain the foetus, it would extend and grow thin in +proportion as the foetus increased in size; but in reality the matrix +not only extends in proportion as the foetus grows larger, but +receives at the same time a thickness and solidity. This augmentation +is a real growth, like the expansion of the body in young animals, +which can only be produced by the intimate penetration of the organic +molecules analogous to the substance of the parts: and as this +expansion of the matrix never happens but after impregnation, we cannot +doubt its being produced by the liquor of the male, especially as the +expansion takes place before the foetus has sufficient bulk to dilate +it. + +It seems certain, by my experiments, that the female has a seminal +liquor which commences to be formed in the testicles, and is completed +in the glandular bodies: this liquor distills through the small holes, +at the extremities of these bodies; and may, like that of the male, +enter into the matrix in two different manners, either by these holes +at the extremities, or through the membraneous coat of the matrix. + +These seminal liquors are both extracts from all parts of the body, and +in the mixture of them there is every thing necessary to form a certain +number of males and females; and the more the animal abounds with this +liquor, and the more that abounds with organic molecules, the greater +is their number of young; as we have already remarked is the case with +the small animals, and diminishes in the large. + +But to pursue our subject with greater attention, we shall first +examine the particular formation of the human foetus, and afterwards +return to the other animals. In the human species, as well as in large +animals, the seminal liquors of the male and female do not contain a +great abundance of organic molecules, and therefore seldom produce +more than one at a time: the foetus is a male, if the number of the +organic molecules of the male predominates in the mixture, and a female +if the contrary; and it resembles the father or the mother as they +happen to abound in the mixture of the two liquors. + +I conceive, therefore, that the seminal liquor of both are two matters +equally active and necessary for generation; and this I think is +sufficiently proved by my experiments, since I have seen the same +moving bodies in the one as the other. I perceived that the liquor +of the male enters into the matrix, where it meets with that of the +female: that they have a perfect analogy, and are both not only +composed of similar parts by their form, but also in their motions and +actions; as we have remarked in Chap. VI. + +By the mixture of these two liquors I conceive the activity of the +organic molecules of each is stopped, and that the actions of one +counterbalance that of the other, insomuch that each particle ceasing +to move, remains in the place most analogous to itself, and that they +will naturally take the same position, and will dispose themselves in +the same order they held in the animal body; those that came from the +head will arrange themselves in the head of the foetus, those of the +back the same, and so of every other part; consequently they will form +a small organized being, in every thing like the animal from which they +are extracted. + +It must be observed that this mixture of organic molecules of the two +sexes contains similar and different particles; the similar ones +are those which have been extracted from every part common to both +sexes. The different particles are those which have been extracted +from the parts whereby the sexes are distinguished; thus there is, +in this mixture, double the number of organic molecules to form the +head, or the heart, or such other parts common to both, whereas there +are only what are requisite to form the parts of the sex. Now the +similar particles may act upon each other without being disordered, +and collect together as if they had been extracted from the same body; +but the dissimilar parts cannot act on each other, nor unite together, +because they have not any relation; hence these particles will preserve +their nature without mixture, and will fix of themselves the first, +without the need of being penetrated by the others. Thus the molecules +proceeding from the sexual parts will be the first fixed, and all the +rest which are common to both, will afterwards fix indiscriminately, +whether they are those of the male or female, and form an organized +being which, in its sexual parts, will perfectly resemble its father, +if it is a male, and its mother if a female; but which may resemble +one another, or both, in all the other parts of the body. + +It seems to me that if this was well understood, we shall in a great +measure be enabled to answer the objections made to the sentiments pf +Aristotle, and which might also be advanced against this system. The +question is, Why each individual, male and female, does not produce of +itself an animal of its own sex? It must be acknowledged this question +seems to carry weight with it; but having reflected a long time on this +subject I think I have found an answer, and which I shall endeavour to +explain. + +It is certainly evident, from what we have said in the preceding +chapters, and the experiments we have described, that reproduction is +effected by the union of organic molecules returned from each part +of the body of the animal, or vegetable, into one or many common +reservoirs; and that they are the same molecules which serve for +nutriment and expansion of the body. This appears to me to have been +so clearly proved, that I apprehend no scruple can remain as to the +foundation of the theory; but I admit there may be some reason to ask, +Why each animal and vegetable does not produce its own likeness, since +each individual returns from every part of its body, and collects +in a common reservoir, all the organic molecules necessary for the +formation of a small organized being? Why then is not this organized +being formed? and why, in almost every animal, is a mixture of the +liquors of the two sexes required to produce an animal? If I content +myself with answering, that in almost all vegetables, and all kinds +of animals which multiply by cutting, that it appears the design of +Nature that each individual should increase its own species, and that +we must regard as an exception to this rule, the use which is made of +the sexes in other kind of animals; it may be said, that the exception +is more universal than the rule itself. This difficulty will be very +little weakened, if we were to say, that each individual perhaps would +produce its like, if it had proper organs, and contained the necessary +matter towards the nutriment of the embryo; because females have both +this matter, and organs, and yet do not produce either male or female +foetus without the intervention of the male; which intervention of +sexes in all animals is essential and absolutely necessary. + +Although the testicles and seminal vesicles of a man, contain all the +necessary molecules to form a male, yet the local establishment and +arrangement of these molecules cannot be made, because the effect of +an union is prevented by the continual circulation of the seed both +by absorption, and the action of the new organic molecules which +constantly come into this reservoir from all parts of the body. The +same circumstances taking place with the organic molecules of the +female, is an evident reason why neither can produce of themselves, +because when the seminal liquors of the male and female are mixed, +they have more analogy to each other, than with the parts of the +body of the female where the mixture is performed. By admitting of +this explication, it may be asked, Why the common mode of generation +in animals does not agree with it; for, upon that supposition, each +individual would produce like snails, and impregnate each other, and +each individual receiving the organic molecules the other furnished, +the union would be made of itself, and by the sole power of the +affinity of these molecules among themselves? I own, if it was by this +cause alone the organic molecules could unite it would be natural +to conclude, that the shortest mode to perform the reproduction of +animals, would be to give to one individual both sexes. But it is +quite contrary to the general rule pursued by Nature, as this manner of +generation is confined to snails, and a small number of other animals. +This answer cannot be said to fully satisfy the question, as it merely +supposes the male does not produce, as it cannot receive any thing from +the female, and that having besides no proper viscera to contain and +nourish the foetus. + +We may also suppose that the activity of the organic molecules, in +the semen of one individual, has need of being counterbalanced by the +activity or force of those of another individual, in order to fix +and bring them into a kind of equilibrium, a state of rest highly +necessary to the formation of the animal; and that this activity in +the organic molecules can only be counterbalanced by there being a +contrary action in those which come from the male, and those proceeding +from the female; so that, in this sense, all living or vegetating +beings must have two sexes, conjointly and separately, to produce +their resemblances. But this answer is too general to be entirely +clear; nevertheless, if we pay attention to all the phenomena, we +shall find some explanation resulting therefrom. The mixture of those +two liquors produces not only a male or female foetus, but also +other organized bodies, which have a kind of growth or expansion. The +placenta, membranes, &c. are produced at the same time as the foetus. +There are, therefore, in the seminal liquor of the male or female, or +in the mixture of both, not only organic molecules necessary for the +production of the foetus, but also those which form the placenta and +membranes. We know not from whence these molecules come, since there +is no part of the body, either of the male or female, from which they +could be sent back. From hence it seems it must be admitted, that the +molecules of the seminal liquors of each, being alike active, form +organized bodies every time they can fix, by acting mutually one on the +other: that the particles employed to form a male, will be those of the +masculine sex, which will fix the first, and form the sexual parts; and +that those common to both sexes will then fix indifferently to form the +rest of the body, and that the placenta and membranes are then formed +from the superabundant particles, which have not been used to form +the foetus; if, as we suppose, the foetus is a male, then there +remains to form the placenta, and membranes, all the organic particles +peculiar to the feminine sex which have not been employed; and also +all those of both which shall not have entered the composition of the +foetus, and which cannot be less than one half. So likewise, if the +foetus is a female, the same abundance will be left for the formation +of the placenta, and membranes, and the whole effects be the same, +excepting it will have the superfluity of the male, instead of that of +the female. + +But, it may be said, that in that case the placenta and membranes +ought to become another foetus, which would be a female, if the +first was a male; and a male if the first was a female; for the first +having consumed the organic molecules of the sexual parts of only +one individual, and half those common to both, there remains all the +molecules of the sexual parts of the other individual, and the other +half of those common to both. To this I answer, that the first union +of the organic molecules prevents a second, at least, under a similar +form; that the foetus, being the first formed, exercises an external +power, which disorders the arrangement of the other organic molecules, +prevents the formation of a second foetus, and throws them into a +state from which the form of the placenta and membranes result. + +We are assured by the experiments and observations we have made, that +every living being contains a great quantity of living and active +molecules. The life of the animal or vegetable appears to be only the +result of all the young lives (if that expression is permitted me) of +each of these active molecules, whose life is primitive, and appears +impossible to be destroyed. We have found these living molecules in +every living or vegetating being, and are assured, that they are alike +necessary for nutrition, and consequently, for the reproduction of +animals or vegetables. It is not, then, difficult to conceive, that a +certain number of those molecules united should compose a living being. +Each of these particles possessing animation, an assemblage of them +must be endowed with life, and thus these living organic molecules, +being common to all living beings, they necessarily form any particular +animal or vegetable, according as they are arranged. Now, this +arrangement absolutely depends on the form of the individuals which +furnish those molecules. If they are furnished by an animal, they will +arrange under the form of an individual like to it, exactly as they +were arranged when they served for the expansion of the animal itself; +but must we not then suppose that this arrangement cannot be made +either in animals or vegetables, but by the means of a kind of base, +round which the molecules might unite to form the foetus? Now, it is +plain, this basis is furnished by particles peculiar to the different +sexes, as I shall explain. + +While the molecules of either sex remain by themselves, their action +produces no effect, because they are without any opposition from any +different kind of particles; but, when these molecules are mixed, then +there are dissimilar parts, and those serve for the base and point of +rest to the other molecules, and fix their activity. + +In this supposition that the organic molecules, which, in the mixture +of the seminal liquors of the two individuals, represent the sexual +parts of the male, can alone serve for a base to the organic molecules +proceeding from every part of the female, and those peculiar to the +female sex as a base to them which are extracted from the male, we +might conclude, that the sexual part of the male infant is formed of +the organic molecules of the father, and from those of the mother, for +the rest of the body: and that, on the contrary, the female partakes +of its mother only in sex, and takes the rest of its body from its +father. Boys, therefore, ought, excepting the parts of the sex, to have +a greater resemblance to their mother than to their father, and girls +more to the father than to the mother; but this consequence is not, +perhaps, conformable to experience. + +By considering, under this point of view, generation by sexes, we +should conclude it to be the most general mode of reproduction, as +it is in fact. Beings, whose organization is the most complete, as +animals, whose bodies compose a whole, which can neither be separated +nor divided, and whose powers are con-centered to one single point, can +only reproduce by this mode; because they contain only particles which +resemble each other, and whose union can only be made by different +particles, furnished by another individual. Those where organization is +less perfect, as that of vegetables, whose bodies may be divided and +separated without being destroyed, can be reproduced by other modes. +First, because they contain dissimilar particles; secondly, because +their forms not being so determinate and fixed as that of animals, +the particles may supply the functions of each other, and change +according to circumstances; as we see roots become branches, and shoot +out leaves when exposed to the air, which causes that the vegetable +particles obtain a local establishment, become fixed, and are enabled +to multiply, by various modes. + +It will be the same with animals, whose organization is less perfect, +as the fresh water polypus, and others, which can reproduce by division +of their parts. These organized beings are not so much a single animal, +as a number united under one common covering, as trees are composed of +a multiplicity of young trees, (see Chap, II.) Pucerons, which engender +singly, also contain dissimilar particles, since, after producing +their young they change into flies which do not produce at all. Snails +communicate mutually these dissimilar particles, and afterwards they +both produce. Thus, in all known matters of generation, we see that the +requisite union of organic particles, can only be made by the mixture +of different particles, which serve as a basis capable of fixing their +motions. + +If to the idea of the word _sex_, we give all the extent here supposed, +we shall say, that sexes are found throughout all nature; for then +sex will mean only the parts which furnish the organic particles, +different from the common particles, and which must serve as a fixed +point for their union. But, enough of reasoning on a question that +can be at once resolved, by saying, that God having created sexes, it +necessarily follows that animals should reproduce by their connection. +In fact, we are not made, as I have formerly said, to give a reason +for every _why_. We are not in a state of explaining _why_ Nature, +almost throughout her works, makes use of sexes for the reproduction of +animals, or why sexes exist; we ought, therefore, to content ourselves +with reasoning on what is, on things as they are, since we cannot go +beyond, by forming suppositions which will remove us from the sphere +we ought to contain ourselves in, and to which the small extent of our +knowledge is limited. + +Quitting, therefore, all doubtful conjectures, I shall rest on facts +and observations. I find, that the reproduction of beings is formed in +many different manners; but, at the same time, I clearly perceive, that +it is by the union of the organic particles sent back from every part +of the individual, that the reproduction of vegetables and animals are +effected. I am certain of the existence of these organic and active +molecules in the seminal liquors of male and female animals and seed +of vegetables; and cannot doubt but every species of reproduction +is accomplished by the union of these organic molecules. Nor can I +doubt, that in the generation of animals, and particularly in that of +man, that the male and female particles mix in the formation of the +foetus, since we see infants which resemble both father and mother; +and what confirms this conclusion is, that those parts, common to both +sexes, mix promiscuously; whereas those never mix which represent the +sexual parts. For we every day see children with eyes like the father, +and the forehead and mouth like the mother; but we never find a like +mixture of the sexual parts; it never happens that they have the +testicles of the father, and the vagina of the mother, for even the +fact of hermaphrodites is very doubtful. + +In the parts of generation of the two sexes in the human species, +there is so much resemblance, and so singular a conformity, that we +might be inclined to think those which appear so different externally, +are at bottom the same organs, only more or less developed; this was +the opinion of the ancients, and M. Daubenton's ideas on this subject +appear to me very ingenious. + +The formation of the foetus is, then, made by the union of the +organic particles contained in the mixture of the seminal liquor +of both sexes; this union produces the local establishment of the +particles, which determines them to arrange themselves as they were in +the individuals which furnished them; insomuch, that the molecules, +which proceed from the head, cannot, by virtue of these laws, place +themselves in the legs, or any other part of the foetus. All these +molecules must be in motion when they unite, and in a motion which must +cause them to tend to a kind of centre, about which the union is made. +This centre, or fixed point, which is necessary to the union of the +molecules, and which, by its re-action and inertia, fixes the activity, +and destroys the motion, is, probably, the first assemblage of the +molecules which proceed from the sexual parts of the other individual; +they must arrange under the form of an organized body which will not be +another foetus, for the reasons we have before given.[AC] + +[AC] In this, as in some other places, our author has gone into a +diffuse repetition which we have considered unnecessary and therefore +avoid. + +On the whole, I conceive there are organic particles of the sexual +parts, which serve as a fixed point, or a centre of union, around which +all the other parts that form the embryo collect. I speak of it only +as probable; but as they are the only particles which differ, I have +thought it more natural to imagine, that it is around these different +particles the union is formed than those which are common to both sexes. + +We have before observed, that those who have imagined the heart was the +first formed, are deceived: those who say it is the blood, are no less +so. All is formed at the same time. If we only consult observation, the +chicken is seen in the egg before it has been sat upon; we perceive the +spine of the back and the head, and, at the same time, the appendages +which form the placenta. I have opened a great number of eggs, before +and after incubation; and I am convinced, by my sight, that the chicken +exists entirely in the middle of the cicatrice, the moment it comes +from the body of the hen. The heat, communicated to it by incubation, +only expands the parts by setting the liquors in motion; but it is not +possible to determine which parts of the foetus are fixed in the +instant of formation. + +I have always said, that the organic molecules were fixed, and that +their uniting was caused only by their loss of motion. This appears +to me certain: for, if we separately examine the seminal liquor of +the male and female, we shall see an infinity of small bodies in +great motion, but being mixed, their motion is instantly suspended, +and heat is necessary to renew their activity; for the chicken which +exists in the centre of the cicatrice is without any motion before +incubation; and even twenty-four hours after, when it begins to become +perceptible with a microscope, there is not the least appearance of +motion then, nor even the day following. During the first day it is +only a small white mucilaginous mass, which is of a consistence on +the second, and insensibly increases, but whose motion is very slow, +and does not at all resemble that of the organic particles which move +rapidly in the seminal liquor. Besides, I have reason to say, that +this motion of the organic molecules is absolutely destroyed; for if +we keep an egg without exposing it to a degree of heat necessary to +expand the chicken, the embryo, although formed entirely, will remain +without any motion; and the organic molecules of which it is composed, +will remain fixed without being able to give motion and life to the +embryo which has been formed by their union. Thus, after the motion +of the organic molecules has been destroyed, after the union of these +molecules, necessary to form an animal body, there is still an external +agent required to animate and give it life and motion; and this agent +is heat, which, by rarefying the liquors, obliges them to circulate +and put also every organ in action, which afterwards do no more than +develope and grow, provided that this external heat continues to assist +them in their functions. + +Before the action of this external heat, not the least appearance of +blood is to be seen; and it is not till twenty-four hours after, that +I have perceived any change in the colour of the vessels. The blood +first appears in the placenta, which communicates with the body of +the chicken: but this blood seems to lose its colour as it approaches +the body of the animal; for the chicken is entirely white, and we +with difficulty discover in the first, second, and third days after +incubation, a few small sanguinary points which are close to the body +of the animal, but which seem not to make part of it, although it is +these sanguinary points which afterwards form the heart. Thus, the +formation of the blood is a change occasioned in the liquors by the +motion heat communicates to them, and this blood is formed even out of +the body of the animal, the whole substance of which is then only a +kind of mucilage, or thick jelly. + +The foetus, as well as the placenta, derives the necessary nutriment +for expansion, by a kind of absorption, and they assimilate the organic +parts of the liquor in which they float: for the placenta cannot be +said to nourish the animal, no more than the animal nourishes the +placenta; since, if the one nourished the other, the first would soon +appear to diminish, while the other increased, whereas both increase +together, I have indeed observed in eggs, that the placenta at first +increases much more in proportion than the foetus, and therefore +it may nourish the animal, or rather convey the nutriment to it, by +intussusception. + +What we have just said concerning the chicken, is easily applied +to the human foetus, which is formed by the union of the organic +molecules of the two sexes. The membranes, and placenta, are formed +from the superabundance of the particles which have entered into the +composition of the embryo: which is then inclosed in a double membrane, +where there is also a quantity of liquor, which is, perhaps, at first, +but a portion of the semen of the father and the mother; and as the +foetus does not quit the matrix, it enjoys, from the instant even +of its formation, an external heat necessary for its expansion; this +heat communicates a motion to liquors, and sets the organs in play, and +blood is formed in the placenta, and in the body of the embryo, by the +motion occasioned by this heat. It may be even said, that the formation +of the blood of the infant is as independent of the mother, as that +which passes into the egg, is of the hen which hatches it, or of the +oven which heats it. + +It is certain, that the foetus, placenta, and membranes, grow by +intussusception: for, in the earliest days of conception, the pouch, +which contains the whole product of generation, is not adherent to +the matrix. De Graaf, in his experiments on doe rabbits, made these +globules, wherein the whole business of generation lies, move about +in the matrix. Thus, in the first stages, they increase and grow by +drawing nutriment from the liquors which bathe the matrix, to which +they are afterwards attached by a mucilage, in which small vessels are +formed with time, as we shall hereafter explain. + +But, not to quit the subject, let us return to the immediate formation +of the foetus, on which there are many remarks to be made, both as +to its situation, and the different circumstances which may prevent or +stop its formation. + +In the human species, the seed of the male enters into the matrix, the +cavity of which is considerable; and when it meets with a sufficient +quantity of female semen, a mixture of the organic particles succeed, +and the formation of the foetus ensues: the whole, perhaps, is done +instantaneously, especially if the liquors are both in an active and +flourishing state. The place where the foetus is formed, is the +cavity of the matrix, because the seed of the male can enter there +more easily than into the trunks; and as this viscera has but one +small orifice, which is always shut, excepting when the ardour of +love causes it to open, the materials of generation remain there +with safety, and scarcely ever reissue but by rare and unfrequent +circumstances: but as the liquor of the male sprinkles the vagina, +before it penetrates the matrix, by the activity of the organic +molecules which compose it, it may go farther into the trunks, and, +perhaps, into the ovarium. As the liquor of the female has already its +perfection in the glandular bodies of the testicles, from which it +flows and moistens the trunks and other parts before it descends into +the matrix, and as it may issue out of the vacuities left around the +neck of the matrix, it is not impossible, that the mixture of the two +liquors may be made in all these different places. It is, therefore, +probable that foetuses are often formed in the vagina, but which fall +out as soon as they are formed, because there is nothing to retain +them. It may also sometimes happen, that foetuses are formed in the +trunks; but this case is very rare, and cannot happen but when the +seminal liquor of the male enters the matrix in great plenty. + +The collection of anatomical observations makes mention of foetuses +not only being found in the trunks, but also in the testicles. In +the History of the Old Academy of Sciences, (vol. II. page 91.) we +meet with an observation on this subject. M. Theroude, a surgeon at +Paris, shewed the academy an unformed mass, which he found in the +right testicle of a girl of eighteen years of age. In it were two +open slits, furnished with hair like two eye-lids, above which was a +kind of forehead, with a black line instead of eyebrows; immediately +over that were many hairs matted together in two separate lines, one +of which was seven, and the other three inches long; under the great +angle of the eye, two of the grinding teeth appeared to shoot, hard, +thick, and white; they had their prongs, and a third tooth thicker than +the rest above them. There appeared likewise other teeth at different +distances from each other: two between these, of the canine nature, +issued from an opening where the ear is placed. In the same volume, +page 144, it is related, that M. Mery found, in the testicle of a woman +who had conceived, a bone of the upper jaw, with many teeth therein, +so perfect that some appeared to be of more than ten years growth. We +find, in the _Journal de Medicine_, for January 1683, published by the +Abbé de la Roque, the history of a lady who died with the ninth child, +which was formed in or near one of the testicles, which is not very +clearly explained. The foetus was about an inch in size, completely +formed, and the sex easily to be distinguished. We also find, in the +Philosophical Transactions, some observations on the testicles of +women, wherein teeth, hair, and bones, have been found. If all these +circumstances are true, we must suppose, that the seminal liquor of +the male sometimes ascends, although very seldom, to the testicles of +the female. Yet, notwithstanding all this, I have some difficulty to +believe it; first, because the circumstances, which appear to prove +it, are extremely rare: secondly, because a perfect foetus has never +been seen in the testicles but by M. Littre, who seems to relate it in +a very suspicious manner: thirdly, because it is not impossible, that +the seminal liquor of the female alone may produce organized masses, +as moles, hair, bones, flesh, and, in short, because if we give credit +to anatomists, foetuses may be formed in the testicles of men, as +well as in those of women: for we find, in the History of the Royal +Academy, vol. II. p. 298, an observation of a surgeon, who says, he +discovered in the scrotum of a man, the figure of a child inclosed in +his membranes: and that the head, feet, eyes, bones, and cartilages, +were distinguishable. If all these observations were equally true, we +must necessarily adopt one of these two hypotheses, either that the +seminal liquor, of each sex, cannot produce any thing without being +mixed with that of the other sex, or that either of them can produce +irregular masses of itself. By keeping to the first, we should be +obliged to admit, to explain in all the circumstances we have related, +that the liquor of the male sometimes ascends to the testicle, and, +by mixing with the seminal liquor of the female, forms organized +bodies; and so may also the female fluid, by being plentiful in the +vagina, penetrate, during the time of copulation, into the scrotum of +the male, nearly as the venereal virus often reaches that part; and +that in this case, an organized body may be found in the scrotum, by +the mixture of the male and female fluids; or, if we admit the other +hypothesis, which appears to be the most probable, and suppose, that +the seminal liquor of each individual may produce organized masses, +then we may be able to say, that all these bony, fleshy, and hairy +productions, sometimes found in the testicles of females, and in +the scrotum of males, may derive their origin from the liquor of +the individual in which they are found. But enough of observations +upon facts, which appear to be as uncertain as inexplicable, for I am +much inclined to believe, that, in certain circumstances, the seminal +liquor of each individual may produce something alone and of itself, +and that young girls might form moles without any communication with +the male, as hens form eggs without having received the cock. I might +support this opinion with observations which appear to me as credible +as those I have quoted. M. de la Saone, physician and anatomist of the +Academy of Sciences, published a memoir on this subject, in which he +asserts, that religious nuns, though strictly cloistered, had formed +moles. Why should that be impossible, since hens form eggs without +communication with the cock? and in the cicatrice of these eggs we +perceive a mole, with appendages, instead of a chicken? The analogy +appears to me to have sufficient power for us, at least to doubt, or +suspend our determination. Be this as it will, it is certain that the +mixture of the two liquors are required to form a foetus, and that +this mixture cannot come to any effect but when it is in the matrix, +where the anatomists have sometimes found foetuses; and it is natural +to imagine, that those which have been found out of the matrix, and +in the cavity of the abdomen, have escaped by the extremity of the +trunks, or by some accidental opening, and that they never fall from +the testicles into the abdomen, because it is almost an impossibility +that the seminal liquor of the male can ascend so high. Leeuwenhoek has +computed the motion of these pretended spermatic animals to be four or +five inches in forty minutes, which would be more than sufficient for +the animalcules to traverse from the vagina into the matrix, from the +matrix into the trunks, and from the trunks into the testicles, in an +hour or two, provided all the liquor had that motion. But how is this +to he conceived, that the organic molecules, whose motion ceases as +soon as the liquid fails, can arrive as far as the testicles, unless +brought there by the liquor in which they swim? This progressive +motion cannot be given by the organic molecules to the liquor which it +contains, therefore, whatever activity these molecules may be supposed +to have, we cannot see how they can arrive at the testicles, and form a +foetus there, unless the liquor itself was pumped up and attracted +thither, a supposition not only gratuitous but even against all human +probability. + +The doubts which this supposition gives rise to, confirm the opinion +that the male fluid penetrates the matrix, and enters therein by the +orifice, or across the membraneous coat of the viscera. The female +fluid may also enter into the matrix, either by the opening at the +upper extremity of the trunks, or across the skin even of the trunks +and matrix. M. de Weirbrech, an able anatomist of Petersburg, confirms +this opinion:----"Res omni attentione dignissima (says he) oblata mihi +est in utero feminę alicujus a me dissectę; erat uterus ea magnitudine +qua esse solet in virginibus, tubęque ambę apertę quidem ad ingressum +uteri, ita ut ex hoc in illas cum specillo facile possem transire +ac flatum injicere, sed in turbarum extremo nulla dabatur apertura, +nullus aditus; fimbriarum enim ne vestigium quidem aderat, sed loco +illarum bulbus aliquis pyriformis materia subalbida fluida turgens, in +cujus medio fibra plana nervea, cicatriculę ęmula, apparebat, quę sub +ligamentuli specie usque ad ovarii involucra protendebatur. + +"Dices, eadem a Regnero de Graaf jam olim notata. Equidem non negaverim +illustrem hunc prosectorem in libro suo de organis mulieribus non modo +similem tubam delineasse, Tabula XIX, fig. 3, sed & monuisse, 'tubas +quamvis secundum ordinariam naturę dispositionem in extremitate sua +notabilem semper coarctationem habeant, pręter naturam tamen aliquando +claudi;' verum enimvero cum non meminerit auctor an id in utraque +tuba ita deprehenderit; an in virgine; an status iste pręternaturalis +sterilitatem inducat: an vero conceptio nihilominus fieri possit; +an a principio vitę talis structura suam originem ducat; sive an +tractu tempora ita degenerare tubę possint; facile perspicimus multa +nobis relicta esse problemata quę, utcumque soluta, multum negotii +facessant in exemplo nostro. Erat enim hęc femina maritata, viginti +quatuor annos nata, quę filium pepererat quem vidi ipse, octo jam +annos natum. Dic igitur tubas ab incunabulis clausas sterilitatem +inducere: quare hęc nostra femina peperit? Dic concepisse tubis +clausis; quomodo ovulum ingredi tubam potuit? Dic coaluisse tubas post +partum: quomodo id nosti? Quomodo adeo evanescere in utroque latere +fimbrię possunt, tanquam nunquam adfuissent? Si quidem ex ovario ad +tubas alia daretur via, pręter illarum orificium, unico gressu omnes +superarentur difficultates; sed fictiones intellectum quidem adjuvant, +rei veritatem non demonstrant; pręstat igitur ignorationem fateri, +quam speculationibus indulgere[AD]." The difficulties which occurred +to this able author are insurmountable in the egg system, but which +disappear in our explanation. This observation seems only to prove what +we have observed, that the seminal liquor of both male and female may +penetrate the coat of the matrix, and enter across the pores of the +membranes; to be assured of it, it is only necessary to pay attention +to the alteration that the seminal liquor of the male causes to the +viscera, and to the kind of vegetation or expansion that it causes +there. Besides, the liquor which issues by the vacuities of De Graaf, +being of the same nature as the liquor of the glandular bodies, it is +very evident that this liquor comes from the testicles, and yet there +is no vessel through which it can pass; consequently we must conclude, +that it penetrates the spongy coat of all these parts, and that it not +only enters the matrix, but even can issue out when these parts are in +irritation. + +[AD] Vide Comment. Acad. Petropol, vol IV. page 261 and 262. + +But even should we refuse this idea of penetration, we cannot deny +that the liquor of the female, which flows from the glandular bodies +of the testicles, may enter by the opening at the extremity of the +trunk, as that of the male does by the orifice of the viscera; and that +consequently these two liquors may mix of themselves in this cavity, +and form there the foetus in the manner we have explained. + + + + +CHAPTER XI. + +OF THE EXPANSION, GROWTH, AND DELIVERY OF THE FOETUS, &C. + + +In the expansion of the foetus, two different degrees of growth make +different kinds of expansion. The first, which succeeds immediately +after the formation of the foetus, is not proportionable in all +the parts of which it is composed. The more distant it is from the +formation, the more in proportion are its parts, and it is only after +it has quitted the womb of its mother that the growth of the parts is +made in nearly an equal manner. It must not be imagined that the figure +of the foetus, at the moment of formation, is absolutely like that of +an adult. It is certain that the embryo contains every part which, must +compose a man, but they differ in their successive expansion. + +In an organized body, as that of an animal, we may suppose some parts +are more essential than others, and though some may be useless or +superfluous, there are some on which the rest seem to depend for their +expansion and disposition. We must consider some as fundamental parts, +without which the animal cannot exist, and which are more accessory and +external, and appear to derive their origin from the first, and which +seem to be formed as much for the ornament, symmetry, and external +perfection of the animal, as for the necessity of its existence, and +the exercise of the essential functions of life. These two kinds of +different parts expand successively, and are almost equally apparent +when the foetus quits the womb; but there are others which Nature +seems to keep in reserve, as the teeth, which do not appear for some +time, and also the glandular bodies in the testicles of females, the +beards of males, &c. which do not shew themselves till the age of +puberty. + +In order to discover the fundamental and essential parts of an animal +body, we must pay attention to the number, situation, and nature of +the whole; those which are simple, those whose position is invariable, +and those without which the animal cannot exist, will be the essential +parts; those, on the contrary, which are double, or in a greater +number, those whose size and position vary, and those which may be +retrenched from the animal without destroying or even doing it an +injury, may be looked upon as less necessary, and more accessory, to +the animal machine. Aristotle has said that the only parts essential to +animals were those with which they take their nutriment, and throw out +the superfluous parts of it from the body. From the mouth to the arms +are simple parts, which no other can supply. The head and spine of the +back are also simple parts, whose position is invariable. The spine of +the back serves for a foundation to the fabric of the body; and it is +from the marrow which it contains that the motion and action of most +of the members and organs proceed; it is also this part which appears +one of the first in the embryo. Now these simple parts which appear +the first are all essential to the existence and form of the animal. +There are many more double than simple parts in the body of an animal, +and seem to be produced on each side of the simple parts by a kind of +vegetation; for these double parts are similar in form, and different +in position. The left hand exactly resembles the right, because it is +composed of the same number of parts; nevertheless, if it was placed +in the situation of the right, we could not make use of it for the +same purposes, and should have reason to regard it as a very different +member. It is the same with respect to the other double parts; they are +similar as to form, and different as to the position which is connected +to the body of the animal; and by supposing a line to divide the body +into two equal parts, the position of all the similar parts would refer +to this line as a centre. + +The spinal marrow, and the vertebrę which contains it, appear to be the +real axis, to which we must refer all the double parts of the animal, +for they seem to derive their origin, and to be only symmetrical +branches issuing from this trunk or common base, for we see the ribs +shoot out on each side of the vertebrę in the young chicken as the +young branches shoot out from the principal branch of a tree. In all +embryos the middle of the head and vertebrę appear to be the first +formed; afterwards we see on the two sides of a vesicle which forms the +middle of the head two other vesicles which appear to proceed from the +first. These two vesicles contain the eyes and the other double parts +of the head; so likewise we perceive little tubercles shoot out in +equal numbers from each side of the vertebrę, which extend by degrees +and form the ribs, and other double parts of the trunk. On the side +of this trunk already formed, as the conclusion, the legs and arms +appear. This first expansion is very different from that which is made +afterwards; it is the production of parts which appear for the first +time; that which succeeds is only a growth of all the parts already +created. + +This symmetrical order of all the double parts found in every animal, +the regularity of their position, the equality of their extension and +growth, and the perfect resemblance between them, seem to indicate that +they derive their origin from the simple parts; that there must reside +in these simple parts a power which acts equally on each side, or, +which answers the same meaning, they are the fixed points against which +the power that produces the expansion of the double parts is exercised. +That the power which acts on the right is equalled by that of the left +side, and consequently they are counterbalanced by this re-action. + +From hence we may infer, that if there is any defect or excess in the +matter which is to serve for the formation of the double parts, as the +powers which impel them on each side are equal, the defect or excess +must be formed the same both on the right and left; for example, if, +from a defect of matter, a man has but two fingers instead of five on +the right hand, he will have but two on the left hand; or if, by an +excess of matter, he has six fingers on one hand, he will have six on +the other; or if the matter be vitiated, and causes an alteration in +the right part, it will be the same on the left. This fact is very +often seen. Most monsters are made with symmetry; the disarrangement +of the parts of monsters appears to be made with order: Nature, +therefore, even in her errors, mistakes as little as possible. + +This harmony of position in the double parts of animals is found also +in vegetables; branches shoot out from buds on every side; the veins in +the leaves are equally disposed as to the principal vein; and although +symmetrical order appears to be less exact in vegetables than in +animals, it is only because it is more varied, and its limits are more +extended, and less precise; but we may nevertheless easily discover +this order, and distinguish the simple and essential parts from those +which are double, and the latter we must regard as having taken their +origin from the former. We shall more fully discuss this point, as far +as relates to vegetables, when we come to treat of them. + +It is not possible to determine under What form the double parts exist +before expansion, nor in what manner they are folded, nor what figure +results from their position by connection with the simple parts. The +body of the animal, in the instant of formation, certainly contains +every part which is to compose it; but the relative position of these +parts must be very different then from what it becomes afterwards. +It is the same with vegetables, for if we observe the expansion of +a young leaf, we shall perceive that it is folded on both sides the +principal vein, and that its figure does not resemble at that time what +it afterwards assumes. + +When we amuse ourselves by folding paper to form crowns, boats, &c. +the different folds of the paper seem to have no resemblance to the +form which must result by the unfolding; we only see that these folds +are always made in an uniform order, and exactly the same on one side +as that we have made on t he other; but it would be a problem beyond +known geometry, to determine the figures which may result from all the +unfoldings of a certain given number of folds. All what immediately +relates to the position, is beyond our mathematical sciences. This art, +which Leibnitz calls _Analysis Situs_, is not yet found out; though the +art, which would shew us the connections that result from the position +of things, would perhaps be more useful than that which has only bulk +for its object, for we have often more need to know the form than the +matter. + +In the unfolding of Nature's productions, not only the folded parts +take new positions, but they acquire, at the same time, extent and +solidity. Since we cannot therefore determine the result of the simple +unfolding of a folded form, in which, as in a piece of folded paper, +there is but one change of position between the parts, without any +augmentation or diminution of the bulk or mass of the matter, how is +it possible for us to judge of the complex unfolding of the body of +an animal, in which not only the relative position of the parts, but +also their mass of matter, undergoes considerable changes? We cannot, +therefore, reason upon this subject, but by drawing some inductions +from the examination of the things at the different periods of their +unfolding, and by assisting ourselves with the observations that we +have had the opportunity to make. + +It is true we see the chick in the egg before incubation; it floats +in a transparent liquor, contained in a small purse, formed by a very +fine membrane in the centre of the cicatrice; but this chick is then +only a particle of inanimate matter, in which we cannot discern any +organization, nor any determined figure. We judge by the external form +that one of the extremities is the head, and the rest to be the spine +of the back. It appears that this is the first product of fecundation +resulting from the mixture of the seed of the male and female; +nevertheless, before asserting this as a fact, there are many things +should be considered. When the hen has cohabited with the cock for a +few days, and afterwards separated from him, the eggs she produces for +a month after separation are as fertile as those she produced during +the time of cohabitation with the male, and unfold at the same time; +they only require twenty-one days sitting, and the embryo of the one +will be as forward and as completely formed as that of the other. From +hence we might think, that this form, under which the chick at first +appears to us in the egg, does not immediately proceed from a mixture +of the two liquors, but that it existed in other forms during the time +the egg remained in the body of the mother; for the embryo in the form +we see it before incubation, requires only heat to unfold and bring it +forth. Now, if it had this form twenty days, or a month before, when +the egg was first fecundated, why was it not hatched by the internal +heat of the hen? and why is not the chicken perfectly formed in those +eggs which are fecundated twenty-one days before the hen lays them? + +This difficulty is not so great as it appears; for we must conceive, +that in the time of the cock's cohabitation with the hen, each egg +receives in its cicatrice, wherein the female liquor is contained, +a small portion of the semen of the male. The egg attached to the +ovary is in oviparous females, what the glandular substance is in the +testicles of viviparous females. The cicatrice of the egg corresponds +with the glandular bodies in which the seminal liquor of the female +resides; that of the male penetrates and mixes there with it; from +this mixture, the formation of the embryo instantly results. The first +egg which the hen lays after coition is fecundated, and capable of +producing a chicken; those which she lays afterwards were fecundated at +the same instant; but as there is still wanting essential parts to this +egg, the production of which is independent of the seed of the male, +as the white, membranes, and shell, the young embryo contained in the +cicatrice cannot unfold in this imperfect egg, although assisted by the +internal heat of the mother. It remains, therefore, in the cicatrice +in the state in which it was formed, until the egg has acquired all +the parts necessary to the growth and nourishment of the chicken: and +it is not till the egg has attained its perfection that the embryo +begins to unfold: this unfolding is performed by the external heat of +incubation; but it is certain, if the egg could be confined within the +body of the hen for 21 days after it was completely formed, the chicken +would be produced, unless the internal heat of the hen should prove too +powerful, for the degrees of heat necessary to hatch chickens are not +very extended, and the least defect or excess is equally prejudicial +to their unfolding. The last eggs the hen lays, containing the same as +the first, proves nothing more than that the egg must acquire entire +perfection before the embryo can unfold itself; and for want of the +heat necessary to this unfolding, eggs may be kept a considerable time +before incubation, without preventing the produce of the chickens they +contain. + +It appears, therefore, that the state of the embryo, when the egg is +laid by the hen, is the first state which succeeds fecundation; that +the form under which we see it is the first form resulting from the +intimate mixture, and form the penetration of the two seminal liquors; +and consequently by following, as Malpighius has done, this unfolding +from hour to hour, we discover all that is possible to be known, unless +we could see the two liquors mix before our eyes, and how the first +arrangement of the particles are made, which produces the first form of +the embryo. + +If we reflect on this fecundation (which is made at the same time) of +these eggs, which are laid successively, and along time after each +other, we shall find new arguments against the existence of eggs in +viviparous animals; for if the females of viviparous animals, or if +women contained eggs, like hens, why are there not many fecund at +the same time? why are not some of them produced in nine months, +and others at distant periods? and when women have two or three +children, why do they all come into the world at one time? If these +foetuses were produced by the means of eggs, would not they come +successively, according as the eggs come to perfection, after the time +of impregnation? And would not super-foetation be as frequent as they +now are scarce, or as natural as they appear to be accidental? + +We cannot follow the unfolding of the foetus in the matrix as we +pursue that of the chick in the egg; the opportunities of observing it +are few, and we can only know what anatomists, surgeons, and midwives +have written thereon. It is by collecting all their particular +observations, and by comparing their remarks and their descriptions, +that we have made the following abridged history of the human foetus. + +There is a great appearance that, immediately after the mixture of +the two seminal liquors, the whole materials of generation exist in +the matrix under the form of a globe; since we know, by anatomists, +that three or four days after conception there is a small oval ball in +the matrix, this ball is formed by an extremely fine membrane, which +incloses a limpid liquor like the white of an egg. We can then perceive +some small united fibres in this liquor, which are the first outlines +of the foetus. A net-work of fine fibres collects on the surface of +the ball, which extends from one of the extremities to the middle. +These are the first vestiges of the placenta. + +Seven days after conception we may distinguish, by the naked eye, the +first lineaments of the foetus, as yet unformed; being only a mass of +transparent jelly, which has acquired some small degree of solidity; +the head and trunk are easily discernible, because this mass is of an +oblong form, and the trunk is more delicate and somewhat longer. Some +small fibres, in form of a plume of feathers, spring from the body +of the foetus, and which turn towards the membrane in which it is +included; these fibres are to form the umbilical cord. + +Fifteen days after conception, the head, and the most apparent +features of the face, are distinguishable; the nose resembles a small +prominent and perpendicular thread affixed to a line, which indicates +the division of the lips. Two small black points are in the places of +the eyes, and two little holes in those of the ears; the body of the +foetus has also received some growth. On each side of the upper and +inferior parts of the trunk, little protuberances appear, which are the +first outlines of the arms and legs. + +Eight days after, that is in three weeks, the body of the foetus +has only increased about a line; but the arms and legs, the hands and +feet, are apparent; the growth of the arms is more quick than that +of the legs, and the fingers separate sooner than the toes. At this +time internal organization begins to be discernible; the bones appear +like small threads as fine as hairs; the ribs are disposed regularly +from the two sides of the back bone; and as well as the arms, legs, +fingers, and toes, are represented by very small threads. + +At a month the foetus is more than an inch long; it naturally takes +a curved posture, in the middle of the liquor which surrounds it, and +the membranes which contain the whole are increased in extent and +thickness; the mass is oval, and it is then about an inch and an half +in its greatest, and an inch and a quarter the smallest diameter. +The human figure is no longer equivocal, every part of the face is +already discernible; the body is fashioned, the thighs and belly are +seen, the limbs formed, the toes and fingers divided, the skin thin +and transparent, the viscera marked by fibres, the vessels as fine +as threads, and the membranes extremely delicate, the bones are as +yet soft, and have only taken solidity in some few parts; the vessels +which compose the umbilical cord, are as yet in a straight line by +the side of each other; now the placenta only occupies a third of the +whole mass; whereas in the beginning it occupied the half. It appears, +therefore, that its growth, in superficial extent, has not been so +great as that of the foetus, and the rest of the mass; but it has +increased much more in solidity; its thickness has become greater in +proportion than the membranes of the foetus, both of which are now +easily distinguished. + +According to Hippocrates, the male foetus is developed sooner than +the female. He says all parts of the body in the first are apparent in +thirty, whereas the latter are not so till the expiration of forty-two +days. + +In six weeks the foetus is nearly two inches long; the human figure +begins to be more perfect; the head is only larger in proportion than +the other parts of the body; the motion of the heart is perceived about +this time. It has been seen to beat in a foetus of sixty days, a long +while after it had been taken out of the womb of its mother. + +In two months the foetus is more than two inches long; the +ossification is discernible as far as the middle of the arm, thigh, +and leg, and in the point of the lower jaw, which is then very forward +before the upper. These, however, are only ossified points; but by the +effect of a more ready expansion, the clavicles are wholly ossified. +The umbilical cord is formed, and the vessels which compose it, begin +to twist nearly like threads which compose a rope: but this cord is +still very short in comparison of what it becomes hereafter. + +In three months the foetus is nearly three inches long, and weighs +about three ounces. Hippocrates says, that it is at this time the +motion of the male foetus begins to be felt by its mother; but that +those of the female are not felt till after the fourth; there are women +who affirm they have felt the motions of the child at the beginning of +the second month. It is very difficult to be certain on this subject, +the sensations excited by the first motions of the foetus depending, +perhaps more on the sensibility of the mother than the strength of the +child. + +Four months after conception the length of the foetus is six or +seven inches; every part of its body is so greatly augmented as to +be perfectly distinguished from each other; even the nails appear on +the fingers and toes. The testicles of the males are shut up in the +belly above the kidneys; the stomach is filled with somewhat of a +thick humour, like that which incloses the amnios. We find a milky +fluid in the little vessels, and in the large ones a black liquid +matter. There is a little bile in the gall, and some urine in the +bladder. As the foetus floats freely in the liquid which surrounds +it, there is always a space between the body and membranes in which it +is contained. These coverings grow at first more than the foetus; +but after a certain time it is quite the contrary. Before the end +of the third month the head is bent forward, the chin rests on the +breast, the knees are lifted up, the legs bent backwards upon the +thighs (sometimes the knees are so high as almost to touch the jaws), +the arms are generally folded across the breast, and one of the +hands, and often both touch the face. The foetus afterwards takes +different situations, as it acquires strength. Experienced midwives +have pretended to be certain that it changes much oftener than is +commonly thought, and which they prove by several observations; first, +the umbilical cord is often found twisted round the body and limbs of +the child, in a manner which necessarily supposes, that the foetus +has moved in many directions, and taken different positions; secondly, +a mother feels the motions of the foetus sometimes on one side of +the womb and sometimes on another; and it often strikes against many +different places, which must be occasioned by different positions, and +supposes that it takes different situations; thirdly, as it floats in +a liquid which surrounds it on all sides, it can very easily turn and +extend itself by its own strength; and it must also take different +situations according to the various attitudes of the mother; for +example, when she lies down, the foetus must be in another situation +to what it was when she stood upright. + +Most anatomists have said, that the foetus is constrained to bend +its body, because it is too confined in its covering; but this opinion +does not appear well founded, for in the first five or six months there +is more space than is required for the foetus to extend, and yet +during that time it is bent and folded. We also see the chicken is in +a curved posture in the liquor of the amnios, although this membrane +and its liquor are sufficient to contain a body five or six times as +large as the foetus. Thus we may conclude that this curved form of +the foetus is natural, and not the effect of force. I am somewhat of +Harvey's opinion, who says, it takes this attitude because it is the +most favourable to rest and sleep; and as the foetus sleeps almost +continually, it naturally takes the most advantageous situation. "Certe +(says this famous anatomist) animalia omnia, dum quiescunt & dormiunt, +membra sua ut plurimum adducunt & complicant, figuramque ovalem ac +conglobatam quęrunt: ita pariter embryones qui ętatem suam maxime +somno transigunt, membra sua positione ea qua plasmantur (tanquam +naturalissima ac maxime indolenti quietique aptissima) componunt[AE]." + +[AE] Harvey on Generation, page 257. + +The matrix, as we have already said, takes a very ready growth after +conception, and it continues also to increase in proportion with the +foetus; but the foetus at length outgrows the matrix, and then, +especially when it approaches maturity, it may be too much confined, +and agitate the matrix by reiterated motions and violent efforts. The +mother sensibly feels the impression of these painful sensations, +and which are called periodic pains after the labour commences. The +more power the foetus exerts to dilate the matrix the greater it +finds the resistance, from the natural compression of the parts. From +thence all the effect falls on the orifice, which has been increasing +by degrees during the latter months of pregnancy. The head of the +foetus, forcibly inclining against the sides of the orifice, dilates +it, by a continual pressure, till the moment of delivery, when it opens +sufficiently for the child to escape from the womb. + +What makes it probable that the labour-pains proceed only from the +dilatation of the orifice of the matrix is, that this dilatation is +the only means to discover whether the pains felt are in fact the +pains of labour, for women often feel very sensible pains, which +are not those that immediately precede delivery. To distinguish +the false from true pains, it has been recommended for the midwife +to touch the orifice of the matrix, as if the pains be true the +dilatation will always increase, and if they are false pains, that +is to say, pains which proceed from some other cause than that of +the approaching delivery, the orifice will contract rather than +dilate, or at least will not continue to dilate. From hence we have +sufficient foundation to imagine, that these pains proceed from a +forced dilatation of the orifice. The only thing which embarrasses on +this occasion is that alternative of rest and sufferings the mother +endures. This circumstance of the effect does not perfectly agree +with the cause which we have just indicated; for the dilatation of +an orifice, which is made by degrees, should produce a constant and +continued pain, without any intervals of ease. But possibly the whole +may be attributed to the separation of the placenta, which we know +is fastened to the matrix by a number of papillę, which penetrate +into the vacuities or cavities of this viscera; therefore may it not +be supposed that they do not separate from their cavities all at the +same time; that each separation causes those acute pains, and the +intervals between are those of ease and rest? The effect in this +case perfectly answers the cause, and we can support this conjecture +by another observation.--Immediately before delivery there issues a +whitish and viscous liquor, like that which flows from the nipples of +the placenta when drawn out of their places, which makes it probable +that this liquor, which then issues from the matrix, is produced by the +separation of some of the papillę of the placenta. + +It often happens that the foetus quits the matrix without bursting +the membranes, and consequently without the contained liquor flowing +out. This kind of delivery appears to be most natural, and resembles +that of most animals; nevertheless, the human foetus commonly pierces +its membranes by the resistance it meets with at the orifice of the +matrix. It also sometimes brings away part of the amnios, and even the +chorion, upon its head like a cap. When these membranes are pierced or +torn, the liquors, called the _waters_, which they contain flow out, +and the sides of the orifice of the matrix, and the vagina, being thus +moistened, give way more easily to the passage of the child. After the +flowing of this liquor there remains sufficient room in the matrix for +the midwife to return the child, if the position is unfavourable. When +the foetus is come out the delivery is not entirely completed, the +placenta and membranes remain in the matrix, and the new-born infant +adheres to them by the umbilical cord; the hand of the midwife, or the +weight of the body of the infant alone, draws them out by means of this +cord. Those organs which were necessary to the life of the foetus +become useless, and even noxious to the new-born infant. They are +instantly separated from the body of the child, by tying the umbilical +cord about an inch distance from the navel, and by cutting it about +an inch from the ligature. The remainder of this cord dries away, and +separates of itself from the navel, about the sixth or seventh day. + +On examining the foetus previous to its birth we may form some idea +of its natural functions. It has organs, which are necessary to it +while in the womb of its mother, but which become useless. For the +better understanding the mechanism of these functions, we must explain +a little more particularly the nature of those necessary parts, the +umbilical cord, the membranes, the liquor which they contain and the +placenta. The umbilical cord, which is attached to the body of the +foetus at the navel, is composed of two arteries and one vein; these +prolong the circulation of the blood, but the vein is larger than the +arteries. At the extremity of the cord each of these vessels divide +into an infinity of ramifications, which extend between two membranes. +They separate at equal distances from the common trunk; so that these +ramifications are round and flat, and are called, when thus collected, +the _placenta_. The external surface, which is applied against the +matrix, is convex; the internal concave. The blood of the foetus +circulates in the cord, and in the placenta. The arteries of the cord +spring from two large arteries of the foetus, and carry the blood +through the arterial ramifications of the placenta; from thence it +passes into the venous branches which carry it into the umbilical +vessels; these communicate with a vein of the foetus, in which +vessels it is received. + +The concave surface of the placenta is clothed by the chorion; the +convex is also covered by a kind of soft membrane, easily torn, which +seems to be a continuation of the chorion, and the foetus is included +under the double coat of the chorion and the amnios. The form is +globular, because the intervals between the membranes and the foetus +are filled with a transparent liquor. This liquor is contained by the +amnios, which is the internal membrane, it is thin and transparent; it +folds round the umbilical cord at its insertion into the placenta, and +covers it the whole length to the navel of the foetus. The chorion +is the external membrane; it is thick and spongy, sprinkled with +sanguinary vessels, and composed of many coats, the exterior of which +covers the convex surface of the placenta. It follows the inequalities, +and covers the papillę, which spring from the placenta, and are +received in the cavities found at the bottom of the matrix, called +_lacunę_. The foetus adheres to the matrix by these insertions. + +Some anatomists have thought that the human form had, like those of +certain quadrupeds; a membrane called _allantois_, destined to receive +the urine; and they have pretended to have found it between the chorion +and the amnios, or in the middle of the placenta at the root of the +umbilical cord, under the form of a very large bladder, in which the +urine entered by a long pipe that composed part of the chord, and which +opened on one side into the bladder, and on the other in this allantois +membrane, being similar to the urachus in other animals. They owned, +however, that it was not near so large in the human foetus as in +quadrupeds, but that it was divided into many tubes, so minute, that +they could scarcely be perceived, and that the urine passed into their +cavities. + +The experience and observations of most anatomists are contrary to +this supposed discovery. They admit there is a kind of ligament which +adheres by one end to the external surface of the bottom of the +bladder, and extends to the navel; but it becomes so delicate, on +entering into the cord, as to be nearly reduced to nothing: in common +this ligament is not hollow, and we can see no orifice at the bottom of +the bladder. + +The foetus has no communication with the open air, and the +experiments made upon the lungs prove they have never respired; for +they sink to the bottom when put in water: whereas those of infants +who have breathed always float on the top; the foetus then does not +respire in the womb, consequently it cannot form any sound by its +voice; and therefore what has been related of the groaning and crying +of children before their birth may be considered as fables. After the +flowing of the waters it may happen, that the air has found an entrance +into the cavity of the matrix, and then the infant may begin to respire +before it is brought forth. In this case it may be able to cry, as +the chicken cries before the shell of the egg is broken, which it can +do from there being air in the cavity which is between the external +membrane and the shell. This air is found in all eggs, and is produced +by the internal fermentation of matters contained in them[AF]. + +[AF] See La Statique des Vegetaux, Chap. vi. + +The lungs of the foetus being without any motion, have no more blood +enter into them than is requisite to nourish and make them grow; and +there is another road opened for the course of its circulation. The +blood in the right auricle of the heart, instead of passing into the +pulmonary artery, and returning, after having ran through the lungs +into the left auricle by the pulmonary vein, passes immediately into +the left by an opening, called the _foramen ovale_, which is in the +partition of the heart between the two auricles. It enters afterwards +into the aorta, which distributes it by its ramifications, at going +out of which the venous branches receive it, and bring it back to the +heart by uniting all in the _vena cava_, which terminates at the right +auricle of the heart. The blood which this auricle contains, instead +of passing entirely by the foramen ovale, may escape in part into the +pulmonary and the aorta by an arterial canal, which goes immediately +from the one to the other. It is by these roads that the blood of the +foetus circulates without entering into the lungs, as it enters into +those of children, adults, and every animal which breathes. + +It has been thought that the blood of the mother passes into the body +of the foetus, by means of the placenta and umbilical cord. It +was supposed that the sanguinary vessels of the matrix opened into +the vacuities, and those of the placenta into the nipples, and that +they joined one to the other; but experience is quite contrary to +this opinion; for if the arteries of the umbilical cord is injected +the liquor returns by the veins, and not any part of it escapes +externally. Besides, the nipples may be drawn from the vacuities +where they are lodged, without any blood issuing either from the +matrix or placenta: a milky liquor only issues from both, and which, +we have already observed, serves the foetus for nutriment. This +liquor possibly enters into the veins of the placenta, as the chyle +enters into the subclavian vein; and perhaps the placenta in a great +measure performs the office of the lungs in bringing the blood to +maturity. It is certain that the blood appears much sooner in the +placenta than in the foetus, and I have often observed in eggs that +have been under the hen for a day or two, that the blood appeared at +first in the membranes, and that their sanguinary vessels are very +large and numerous, while the whole body of the chicken, excepting +the point where these blood-vessels terminate, is only a white and +almost transparent matter, in which there is not the smallest sign of a +sanguinary vessel. + +It has been imagined, that the liquor of the amnios is a nutriment +the foetus receives by its mouth. Some naturalists pretend to have +observed this liquor in the stomach, and to have seen some foetuses +to which the umbilical cord was entirely wanting, and others who had +but a very small portion, which did not at, all adhere to the placenta; +but in this case might not the liquor have entered into the body of +the foetus by the small portion of the umbilical cord, or by the +umbilical vessel itself? Besides, to these observations we may oppose +others. Some foetuses have been found whose lips were not separated, +and others without any opening in the oesophagus. To conciliate +these circumstances, some anatomists have thought that the aliments +passed into the foetus partly by the umbilical cord, and partly by +the mouth: none of these opinions appear to have any foundation. It +is not the question to examine the growth of the foetus alone, and +to seek from whence and by what it draws its nutriment, but how the +growth of the whole is made; for the placenta, liquor, and membrane +increase in size as well as in the foetus; and consequently the +instruments and canals employed to receive or carry this nutriment to +the foetus, have a kind of life themselves. The expansion of the +placenta and membranes is as difficult to conceive as that of the +foetus; and we might say, with equal propriety, that the foetus +nourishes the placenta, as that the placenta nourishes the foetus. +The whole mass is floating in the matrix, and without any adherence at +the commencement of this growth: therefore the nourishment can be only +made by an absorption of the milky matter contained in the matrix. The +placenta appears first to draw this nutriment, to convert this milk +into blood, and to carry it to the foetus by veins. The liquor of the +amnios appears to be only this milky liquor depurated, the quantity of +which increases by a like absorption, proportionate to the increase +of the membranes, and the foetus probably absorbs the liquor, which +appears to be the necessary nutriment for its expansion. For we must +observe, that for the first two or three months the foetus contains +very little blood; it is as white as ivory, and appears to be composed +of lymph which has taken some solidity; and as the skin is transparent, +and all the parts very soft, we may easily conceive that the liquor +in which the foetus swims may penetrate them, and thus furnish the +necessary matter for its nutrition and expansion. It may be supposed +that the foetus in the latter stages takes its nutriment by the +mouth, since in the stomach we find a liquor similar to that in the +amnios, urine in the bladder, and excrements in the intestines; and as +we find neither urine nor _meconium_ in the amnios, there is reason to +conclude that the foetus does not void its excrements, especially +as some are born without having the anus pierced, although they had a +great quantity of _meconium_ in the intestines. + +Although the foetus does not immediately adhere to the matrix, but +is only attached to it by small external nipples, though it has no +communication with the blood of its mother, but is as independant of +her who bears it, in many respects, as the egg is of the hen that +hatches it, yet it has been pretended, that all which affects the +mother affects the foetus; that the impressions of the one act on +the brain of the other; and to this imaginary influence resemblances, +monsters, and especially marks on the skin of some children, have been +attributed. I have examined many of these marks, and they all appear +to me to have been caused by a derangement in the texture of the +skin. Every mark must have a figure which will resemble something or +other; but I am certain the resemblances so formed depend rather on +the imagination of those who see them than on that of the mother. On +this subject the marvellous has been carried as far as it could go. It +has not been only said that the foetus carried real representations +of the longings of its mother, but that, by a singular sympathy, the +marks, which represent strawberries, cherries, &c. change their colour, +and become deeper in the season of those fruits. With a little more +consideration, and less prejudice, this colour may be seen to change +much oftener, and that it must happen every time the motion of the +blood is accelerated, whether by the heat of summer or from any other +cause. These marks are either yellow, red, or black, because the blood +gives these tints to the skin when it enters in too great quantities +into the vessels. If these marks have the longings of the mother for +their cause, why have they not the forms and colours as varied as the +objects of her desires? What a curious assemblage of figures would be +seen if all the whimsical desires of the mother were written on the +skin of the child? + +As our sensations have no resemblance to the objects which cause +them, it is impossible that desire, fear, horror, or any passion, or +internal emotion, can produce real representations of those objects; +and the child being in this respect as independant of the mother as the +egg is of the hen, I should as soon believe that a hen, which saw the +neck of a cock twisted, would hatch chickens with wry necks, as that, +by the power of imagination, a woman, who happened to see a man broke +upon the wheel, would bring forth a child with its limbs broken in the +same manner. + +But even supposing this circumstance attested, I should still support +the opinion, that the imagination of the mother had not been the cause, +for what is the effect of horror? an internal motion, a convulsion +in the body of the mother, which might shake, compress, and agitate +the womb. What can result from this commotion? nothing similar to the +cause, for if this commotion was very violent the foetus might be +killed, wounded, or deformed in some of its parts; but how is it to +be conceived that this commotion can produce any thing resembling the +fancy of the mother in the foetus, unless we believe, with Harvey, +that the matrix has the faculty of conceiving ideas, and realizing them +on the foetus? + +But, it may be urged, if it was not affected by the imagination of +the mother, why did the child come into the world with broken limbs? +However rash it may appear to explain a matter which is extraordinary +and uncertain, and of which we have no right to exact a solution, +yet this question appears to me answerable in a satisfactory manner. +Circumstances of the most rare and extraordinary kind happen as +necessarily as those which are frequent and common. In the infinite +combinations which matter can take, the most extraordinary arrangements +must sometimes happen; hence we might venture to wager, that in a +million, or a thousand millions of children, there will be one born +with two heads, four legs, or with broken limbs; it may, therefore, +naturally happen, without the concurrence of the mother's imagination, +that a child should be born with broken limbs. This may have happened +more than once, and the mother, while pregnant, might have been +present at the breaking on the wheel, and therefore the defect of the +child's formation has been attributed to what she had seen, and to +her impressed imagination. But, independant of this general answer, +we may give a more direct explanation. The foetus, as we have +said, has nothing in common with the mother; its functions, organs, +blood, &c. are all particular, and belong to itself; the only thing +which it derives from its mother is the liquor, or nutritive lymph, +which filtrates from the matrix. If this lymph is bad, or envenomed +with the venereal virus, the child will be alike disordered; and it +may be imagined, that all the diseases which proceed from vitiated +humours may be communicated from the mother to the child. We know that +the small-pox is communicative, and we have but too many examples +of children who are, directly after their birth, the victims of the +debauches of their parents. The venereal virus attacks the most solid +parts of the bones, and it appears to act with more force towards +the middle of the bone, where ossification commences; I conceive, +therefore, that the child here spoken of has been attacked by the +venereal disorder while in its mother's womb, and from that cause it +came into the world with its bones broken through the middle. + +Rickets may also produce the same effect. There is a skeleton of a +rickety child in the French king's cabinet, whose arms and legs have +callosities in the middle of their bones. By the inspection of this +skeleton, it appeared evident that the bones had been broken during the +time it was in the womb, and that afterwards the bones re-united, and +formed these callosities. + +But enough of a subject which credulity alone has rendered marvellous. +Prejudice, especially that sort which is founded on the marvellous, +will always triumph over reason, and we should have but little +philosophy if we were astonished at it. We must not therefore ever +expect to be able to persuade women, that the marks on their children +have no connection with their unsatisfied longings. Yet might it not be +asked them, before the birth of the child, of what particular longings +they had been disappointed, and consequently what will be the marks +their children will bear? I have often asked this question, and have +only made persons angry without having ever convinced them. + +The time that a woman goes with child is generally about nine months; +but it is however sometimes longer and sometimes shorter. Many children +are born at seven or eight months, and some not till after the ninth; +but in general the deliveries which precede the term of nine months +are more frequent than the others. The common time of a natural +delivery extends to twenty days, that is, from eight months fourteen +days to nine months and four hours. + +Many children are born before the 260th day, and although these +deliveries precede the general term, they are not abortions, because +these children mostly live. It is commonly thought that children born +at eight months cannot live, or at least that many more of them die +than those born at seven months. This opinion appears to be a paradox; +and by consulting experience I think we shall find it an error. The +child brought forth at eight months is more formed, and consequently +more vigorous, and likely to live than that which is born at the +seventh. Nevertheless this opinion is pretty generally received, and +founded on the authority of Aristotle. + +The beginning of the seventh month is the earliest term for delivery; +if the foetus is brought forth sooner it dies, and is termed an +abortion. There are, however, great limits for the time of human +delivery, since they extend from the seventh to the tenth, and perhaps +to the eleventh month. + +Women who have had many children assert, that girls remain longer +in the womb than boys. If this is really the case, we must not be +surprized at female children being born at ten months. When children +come before nine months they are not so well proportioned as those +who are not brought into the world till ten months, the bodies of the +latter are sensibly larger and better formed; their hair is longer, +the growth of the teeth, although still hid under the gums, is more +advanced; the voice is clearer, and the tone more deep. + +There is much uncertainty on the occasional causes of delivery, and we +do not perfectly know what obliges the infant to quit the womb. Some +imagine, that the foetus having acquired a certain size, the matrix +is too confined for its longer stay, and that the constraint felt +by the foetus, obliges it to use every effort to quit its prison; +others say, and it is nearly to the same purport, that the weight of +the foetus becomes so great, that the matrix is forced to open to +free itself from the burthen. These reasons do not appear satisfactory; +for the matrix must always have capacity and strength to contain +and sustain the weight of a foetus of nine months, since it often +contains two, and it is certain that the weight and size of the twins +of eight months are more considerable than the weight and size of a +single child of nine. Besides, it often happens that a child born at +nine months is smaller than the foetus of eight months, although it +continues in the womb. + +Galen pretends, that the child remains in the matrix till it is able +to receive its food by the mouth, and that it only forces its escape +from the need of nutriment. Others have said, that the foetus always +receives its nourishment by the mouth from the liquor of the amnios; +but which becomes at length so contaminated, by the transpiration and +urine of the foetus, that it becomes disgustful, and obliges the +foetus to use every exertion to quit its confinement. These reasons +do not appear better than the first; for it would from thence follow, +that the weakest and smallest foetuses would remain longer in the +womb than the strongest and largest, which never happens; besides, +it is not food that the foetus seeks immediately after it is born, +for it can stay some time without it; on the contrary, it seems most +desirous to disembarrass itself from the nutriment it took when in the +womb of its mother, and to return the meconium. Other anatomists have +supposed that the excrement accumulated in the bowels of the foetus, +gives it great pain, and causes it to make such efforts, that the +matrix is at length obliged to give way, and to open a passage for its +escape. I acknowledge I am not better satisfied with this explanation +than the rest; because, why cannot the foetus void its excrements +in the amnios, if it was pressed so to do? Now this never happens; it +appears, on the contrary, that this necessity of voiding the meconium +is not felt till after the birth, when the motion of the diaphragm, +occasioned by that of the lungs, compresses the intestines and causes +this evacuation; for the meconium has never been found in the amnios of +a foetus of ten months who had not respired, whereas a foetus of +six or seven months voids this meconium a short time after respiration. + +Other anatomists, and among them Fabricius de Aquapendente, have +supposed the foetus quitted the matrix through the need of procuring +refreshment by means of respiration. This cause appears to me still +more remote than all the rest, because the foetus can have no idea of +respiration without having respired. + +After having weighed all these explanations, I suppose the foetus's +quitting the matrix depends on a quite different cause. The flowing of +the menstrua is periodical, and at determined intervals; and although +conception suppresses its appearance, it does not destroy the cause; +for notwithstanding the blood does not appear at the accustomed times, +yet a kind of revolution takes place, like that which is made before +conception. Thus it is, there are many women whose menstrua are not +suppressed in the first two or three months. I imagine, therefore, +that when a woman has conceived, the periodical revolution is made as +regular as before; but as the matrix is swelled, the excretory canals +cannot give issue to the blood, at least unless it arrives there with +such force, and in such quantities, as to open a passage in spite of +the resistance, that is opposed to it. In this case blood will appear, +and if it flows in a great quantity abortion will ensue, and the matrix +take the form it had before. But if the blood only forces one part +of these canals, the business of generation will not be destroyed, +although the blood appears, because the greatest part of the matrix +still remains in the state which is necessary for that purpose. + +When no blood appears, as is generally the case, the first periodical +revolution is remarkable and felt by the same pains and symptoms. From +the first suppression of the menses, therefore, a violent action on +the matrix is made, and provided the action is augmented, it destroys +the product of generation. It may from thence be concluded, that every +conception which is made just before the useful return of the menses +seldom succeeds, and that the action of that blood easily destroys the +weak roots of a germ so tender and so delicate. The conceptions, on the +contrary, which are made just after the periodical evacuations succeed +the best, because the produce of the conception has more time to grow, +strengthen, and resist the action of the blood, by the time the next +revolution happens. + +The foetus having undergone this first trial, and having resisted +it, receives more strength and growth, and is more in a condition to +contend against the succeeding revolutions. Miscarriages may and do +happen in all the periodical revolutions; but they are less frequent +in the fourth and fifth months, than either at the beginning or near +the end. We have assigned the reasons why they are more frequent at the +beginning; it therefore only remains to explain why they are also more +frequent towards the end. + +The foetus generally comes into the world during the tenth +revolution. When it is born at the eighth or ninth it lives, and these +deliveries are not looked upon as miscarriages, because the child, +although not so perfectly formed, is still sufficiently so for the +purpose of life. It has been pretended, that examples have been seen +of children born at the seventh and even at the sixth revolution, that +is, at five or six months, which have lived. There is, therefore, no +difference between a birth and a miscarriage but what is relative to +the living powers of the infant. In general the number of miscarriages +in the first, second, and third months are very considerable for the +reasons we have given ; and the number of deliveries of the seventh and +eighth months are also very great, in comparison with the miscarriages +of the fourth, fifth, and sixth months, because in this middle period +the product of generation has received more solidity and strength, and +having resisted the action of the four first periodical revolutions, a +more violent force than the preceding is required to destroy it. The +same reason subsists, with additional force, for the fifth and sixth +months. But the foetus, which till then is weak, and can act only by +its own feeble strength, begins to get strong, and move with vigour; +and at the eighth revolution the foetus, uniting its efforts with +those of the matrix, facilitates its exclusion, and it may come into +the world in the seventh month, and be capable of living, especially +if it happens, as is sometimes the case, to have more than ordinary +strength for that period. But if it comes into the world only through +the weakness of the matrix, which could not resist the action of the +blood in this eighth revolution, the delivery would be regarded as a +miscarriage, and the child would not live. But these cases are very +rare, for if the foetus has resisted the seven first revolutions, +only particular accidents can prevent it from resisting the eighth. The +foetus, which has acquired this same degree of strength and vigour +only a little later, will come into the world at the ninth revolution; +and those which require nine months to obtain this same strength, will +come at the tenth revolution, which is the most common and general +term; but when the foetus has not acquired in nine months this degree +of perfection, it may remain in the womb till the eleventh, and even +till the twelfth revolution; that is, till the tenth or eleventh month, +as we have many examples. + +This opinion, that it is the menstrua which is the occasional cause of +delivery at different times, may be confirmed by many other reasons. +The females of every animal which have no menses, bring forth at +nearly the same terms, and there is but a very slight variation in +the duration of their gestation. We may, therefore, suppose that this +variation, which is so great in women, comes from the action of the +menstrual blood, which is constantly exerted at every periodic return. + +We have observed, that the placenta adheres to the papillę, or the +matrix, only by nipples; that there is no blood either in these +nipples or in the vacuities they are niched into, and that when they +are separated (which is easily done) a milky liquor only issues from +them. Now, how happens it that delivery is always accompanied with a +considerable hęmorrhage, at first of pure blood, and afterwards mixed +with a watery liquor? This blood does not proceed from the separation +of the placenta, as the nipples are drawn out without any effusion of +blood. Delivery, which entirely consists, of this separation, should +not, therefore, produce any blood. Is it not then more accordant with +reason to suppose, that it is the action of the blood which causes +delivery, and that it is this menstrual blood which forces the vessels +as soon as the matrix is emptied, and which begins to flow immediately +after delivery as it did before conception? + +It is known, that in the first months of pregnancy that which +contains the seed of generation is not adherent to the matrix. By +the experiments of De Graaf it has been seen, that by blowing on the +little ball we can make it move. The adhesion to the matrix is never +very strong, and at first the placenta with difficulty adheres to the +internal membrane of the viscera, and those parts are only contiguous, +or joined by a mucilaginous matter, which has scarcely any adhesion. +Why then does it occur, that in miscarriages of the first and second +month this ball never escapes without a great effusion of blood? It is +certainly not caused by the passage of the ball quitting the matrix, +since it does not adhere to it; but it is, on the contrary, by the +action of this blood that the ball is driven out. Must we not then +conclude this blood to be menstrual, which by forcing the canals, +through which it had been accustomed to pass before impregnation, +destroys the product of conception by retaking its common road? + +It appears, therefore, that the periodical revolution of the menstrual +blood has great influence on delivery, and that it is the cause why the +times of delivery in women vary so much more than in every other female +who is not subject to the periodical evacuation, and which always +bring forth at the same times. It also appears that this revolution, +occasioned by the action of the menstrual blood, is not the sole cause +of birth, but that the action of the foetus itself contributes +towards it, since there are instances of a child escaping from the womb +after the death of the mother, which necessarily supposes an action +proper and particular in itself. + +The space of time which cows, sheep, and other animals go with young +is always the same, and their deliveries are not attended with an +hęmorrhage. May we not then conclude, that the blood voided by women +after delivery is the menstrual blood, and that the human foetus +being born at such different terms, can only be by the actions of this +blood on the matrix during every periodical revolution? It is natural +to imagine, that if the females of viviparous animals had menses like +women, their deliveries would be followed with an effusion of blood, +and happen at different terms. The foetuses of animals come into the +world clothed with their membranes (and it seldom happens that the +membranes are broken), and the waters flow before the delivery; whereas +it is very rare a child is brought forth with its membranes entire. +This seems to prove that the human foetus makes more efforts than +other animals to quit its prison; or that the matrix of a woman does +not so naturally incline to the passage of the child, for it is the +foetus which tears its membranes, by the efforts it makes against the +resistance it meets with at the orifice of the viscera. + + +RECAPITULATION. + +All animals procure nutriment from vegetables, or other animals which +feed upon vegetables; there is, therefore, one common matter to both, +which serves for the nutrition and expansion bf every thing which +lives or vegetates. This matter cannot perform them but by assimilating +itself to each part of the animal or vegetable, and by intimately +penetrating the texture and form of these parts, which I have called +the _internal mould_. When this nutritive matter is more abundant than +is necessary to nourish and expand the animal or vegetable, it is +sent back from every part of the body, and deposited in one or more +reservoirs, in the form of a liquor; this liquor contains all the +molecules analogous to all parts of the body; and consequently all +that is necessary for the reproduction of a young being, perfectly +resembling the first. Commonly this nutritive matter does not become +superabundant, in most kinds of animals, till they have acquired the +greatest part of their growth; and it is for this reason that animals +are not in a state of engendering before that time. + +When this nutritive and productive matter, which is universally +spread abroad, has passed through the internal mould of an animal or +vegetable, and has found a proper matrix, it produces an animal or +vegetable, of the same kind; but when it does not meet with a proper +matrix, it produces organized beings different from animals and +vegetables, as the moving and vegetating bodies seen in the seminal +liquor of animals, in the infusion of the germ of plants, &c. + +This productive matter is composed of organic particles, always active, +the motion and action of which are fixed by the inanimate parts of +matter in general, and particularly by oily and saline bodies, but as +soon as they are disengaged from this foreign matter, they retake their +action, and produce different kinds of vegetations and other animated, +beings. + +By the microscope, the effects of this productive matter may be +perceived in the seminal liquors of animals of both sexes. The seed of +the female viviparous animals is filtered through the glandular bodies +which grow upon their testicles, and these glandular bodies contain a +large quantity of seminal fluid in their internal cavities. Oviparous +females have, as well as the viviparous, a seminal liquor, which is +still more active than the viviparous. The seed of the female is in +general like that of the male, when, they are both in a natural state: +they decompose after the same manner, contain similar organic bodies, +and they alike offer the same phenomena. + +All animal or vegetable substances include a great quantity of this +organic and productive matter. To perceive it, we need only separate +the inanimate parts in which the active particles of this matter are +engaged. And this is done by infusing animal or vegetable substances +in water. The salts will dissolve, the oils separate, and the organic +particles will be seen by their putting themselves in motion. They are +in greater abundance in the seminal liquors than in any other parts, +or rather, they are less entangled by the inanimate parts. In the +beginning of this infusion, when the flesh is but slightly dissolved, +the organic matter is seen under the form of moving bodies, which are +almost as large as those of the seminal liquors: but, in proportion as +the decomposition augments, these organnic particles diminish in size +and increase in motion; and when the flesh is entirely decomposed, +or corrupted, these same particles are exceedingly minute, and their +motion exceedingly rapid. It is then that their matter may become a +poison, like that of the tooth of a viper, wherein Mr. Mead perceived +an infinite number of small pointed bodies, which he took for salts, +although they are only these same organic particles in a state of +great activity. The pus which issues from wounds abounds with little +insects, and it may take such a degree of corruption as to become +one of the most subtle poisons; for every time this active matter is +exalted to a certain point, which may be known by the rapidity and +minuteness of the moving bodies it contains, it will become a species +of poison. It is the same with the poison of vegetables. The same +matter which serves to feed us when in its natural state, will destroy +us when corrupted. Spurred barley, for instance, throws the limbs of +men and animals into a gangrene who feed on it. It is also evident by +comparing the matter which adheres to our teeth, which is the residue +of our food, with that from the teeth of a viper or mad dog, which is +only the same matter too much exalted, and corrupted to the last degree. + +When this organic and productive matter is found collected in a great +quantity in some part of an animal, where it is obliged to remain, +it forms living beings which have been ever regarded as animals; +the tęnia, ascarides, all the worms found in the veins, liver, in +wounds, in corrupted flesh, and pus, have no other origin; the eels in +paste, vinegar, and all the pretended microscopical animals are only +different forms which this active matter takes of itself, according to +circumstances, and which invariably tends to organization. + +In all animal and vegetable substances, decomposed by infusion, this +productive matter manifests itself immediately under the form of +vegetation. Filaments are seen to form, which grow and extend like +plants. Afterwards these extremities and knots swell and burst, to give +passage to a multitude of bodies in motion, which appear to be animals; +so that it seems as if all nature began by a motion of vegetation. It +is seen by microscopical objects, and likewise by the expansion or +unfolding of the animal embryo; for the foetus at first has only a +species of vegetable motion. + +Sound food does not furnish any of these moving molecules for a +considerable time. Several days infusion in water is required for fresh +meat, grain, kernels, &c. before they offer to our sight any moving +bodies; but the more matters are corrupted, decomposed, or exalted, the +more suddenly these moving bodies manifest themselves; they are all +free from other matters in seminal liquors; but a few hours infusion +is required to see them in pus, spurred barley, honey, drugs, &c. + +There exists therefore, an organic matter, universally diffused in +all animal and vegetable substances, which alike serves for their +nutrition, their growth, and their reproduction. Nutrition is performed +by the intimate penetration of this matter in all parts of the animal +or vegetable body. Expansion or growth is only a kind of more extended +nutrition, which is made and performed as long as the parts have +sufficient ductility to swell and extend; and reproduction is made +by the same matter when it superabounds in the body of the animal +or vegetable; each part of the body sends back, to the appropriate +reservoirs, the organic particles which exceed what are sufficient +for their nourishment. These particles are absolutely analogous to +each part from which they are sent back, because they were destined +to nourish those parts from hence, when all the particles sent back +from, collect together, they must form a body similar to the first, +since each particle is like that part from which it was detached; thus +it is that reproduction is effected in all kinds of trees, plants, +polypuses, pucerons, &c. where one individual can produce its like; and +it is also the first mode which Nature uses for the reproduction of +animals which have need of the communication of different sexes; for +the seminal liquors of both sexes contain all the necessary molecules +for reproduction; but something more is required for its effectual +completion, which is the mixture of these two liquors in some places +suitable to the expansion of the foetus which must result therefrom, +which place is the matrix of the female. + +There are, therefore, no pre-existing germs, no germs contained one in +the other, _ad infinitum_; but there is an organic matter perpetually +active, and always ready to form, assimilate, and produce beings +similar to those which receive it. Animals and vegetables, therefore, +can never be extinct; so long as there subsist individuals the species +will ever be new; they are the same at present as they were three +thousand years ago, and will perpetually exist, by the powers they are +endowed with, unless annihilated by the will of the Almighty Creator. + + + + +HISTORY OF MAN. + + + + +CHAPTER I. + +OF THE NATURE OF MAN. + + +Though so much interested in acquiring a thorough knowledge of +ourselves, yet I do not know if man is not less acquainted with the +human, than with any other existence. Provided by nature with organs, +calculated solely for our preservation, we only employ them to receive +foreign impressions. Intent on multiplying the functions of our senses, +and on enlarging the external bounds of our being, we rarely make use +of that internal sense which reduces us to our true dimensions, and +abstracts us from every other part of the creation. It is, however, by +a cultivation of this sense alone that we can form a proper judgment +of ourselves. But how shall we give it its full activity and extent? +How shall the soul, in which it resides, be disengaged from all the +illusions of the mind? We have lost the habit of employing this sense; +it has remained inactive amidst the tumult of our corporeal sensations, +and dried up by the heat of our passions; the heart, the mind, the +senses, have all co-operated against it. + +Unalterable in its substance, and invulnerable by its essence, it +still, however, continues the same. Its splendor has been overcast, +but its power has not been diminished: it may be less luminous, but +its guidance is not the less certain. Let us then collect those rays, +of which we are not yet deprived, and its obscurity will decrease; and +though the road may not in every part be equally filled with light, we +yet shall have a torch that will prevent us from going astray. + +The first and most difficult step which leads to the knowledge of +ourselves, is a distinct conception of the two substances that +constitute our being. To say simply, that the one is unextended, +immaterial, and immortal, and that the other is extended, material, and +mortal, is only to deny to the one, what we affirm the other possesses. +What knowledge is to be acquired from this mode of negation? Such +negative expressions can exhibit no positive ideas: but to say that we +are certain of the existence of the former, and that of the latter is +less evident; that the substance of the one is simple, indivisible, and +has no form, since it only manifests itself by a single modification, +which is thought; that the other is a less substance than a subject, +capable of receiving different forms, which bear a relation to our +senses, but are all as uncertain and variable as the organs themselves; +that is to say something; it is to ascribe to each such distinct and +positive properties as may lead us to an elemental knowledge of both, +and to a comparison between them. + +From the smallest reflection on the origin of our knowledge, it is +easy to perceive that it is by comparison alone we acquire it. What +is absolutely incomparable, is utterly incomprehensible; of this +God is the only example; he exceeds all comprehension, because he +is above all comparison. But whatever is capable of being compared, +contemplated, and considered relatively, in different lights, may +always come within the sphere of our understanding. The more subjects +of comparison we have for examining any object, the more methods there +are for obtaining a knowledge of it, and with greater facility. + +The existence of the soul is fully demonstrated. To be and to think are +with us identically the same. This truth is more than intuitive; it is +independent of our senses, of our imagination, of our memory, and of +all our other relative faculties. The existence of our bodies, and of +external objects, is however held in uncertainty by every unprejudiced +reasoner; for what is that extension of length, breadth, and thickness, +which we call our body, and which seems to be so much our own, but as +it relates to our senses? What are even the material organs of those +senses, but so many conformities with the objects that affect them? +And with regard to our internal sense, has it any thing similar or +in common with these external organs? Have the sensations excited by +light or sound any resemblance to that tenuous matter, which seems to +diffuse light, or to that tremulous undulation, which sound produces in +the air? The effects are certainly produced by the necessary conformity +there is between the eyes and ears, and those matters which act upon +them. Is not that a sufficient proof, that the nature of the soul is +different from that of matter? + +It is then a certain truth, that the internal sensation is altogether +different from its cause; as also, if external objects exist, they are +in themselves very different from what we conceive them. As sensation +therefore bears no resemblance to the thing by which it is excited; +does it not follow, that the causes of our sensations, necessarily +differ from our ideas of them? The extension which we perceive by our +eyes, the impenetrability, of which we receive an idea by the touch in +all those qualities, whose various combinations constitute matter, are +of a doubtful existence; since our internal sensations of extension, +impenetrability, &c. are neither extended nor impenetrable, and have +not even the smallest affinity with those qualities. + +The mind being often affected with sensations, during sleep, very +different from those which it has experienced by the presence of +the same objects, does it not lead to a belief, that the presence +of objects is not necessary to the existence of our sensations; and +that, of consequence, our mind and body may exist independent of +those objects? During sleep, and after death, for example, our body +has the same existence as before; yet the mind no longer perceives +this existence, and the body with regard to us, has ceased to be. The +question is therefore, whether a thing which can exist, and afterwards +be no more, and which affects us in a manner altogether different from +what it is, or what it has been, may yet be a reality of indubitable +existence. + +That something exists without us, we may believe, though not with a +positive assurance; whereas of the real existence of every thing within +us, we have a certainty. That of our soul, therefore, is incontestable, +and that of our body seems doubtful; because the mind has one mode of +perception when we are awake, and another when we are asleep; after +death, it will perceive by a method still more different, and the +objects of its sensations, or matter in general, may then cease to +exist with respect to it, as well as our bodies with which we have no +further connection. + +But let us admit this existence of matter; and that it even exists as +it appears to our senses, yet by comparing the mind with any material +object, we shall find differences so great, and qualities so opposite +that every doubt will vanish of the latter being of a nature totally +different, and infinitely superior. + +The mind has but one form, which is simple, general, and uniform. +Thought is this form; has nothing in it of division, extension, +impenetrability, nor any other quality of matter; of consequence, +therefore, our mind, the subject of this form, is indivisible, and +immaterial. Our bodies on the contrary, and all other objects have +many forms, each of which is compounded, divisible, variable, and +perishable; and has a relation to the different organs, through which +we perceive them. Our bodies, and matter in general, therefore, have +neither permanent, real, nor general properties, by which we can +attain a certain knowledge of them. A blind man has no idea of those +objects, which sight represents to us; a leper, whose skin has lost +the sense of feeling, is denied all the ideas which arise from the +touch; and a deaf man has no knowledge of sounds. Let these three +modes of sensation be successively destroyed, yet the mind will exist, +its external functions will subsist, and thought will still manifest +it within the man so deprived. But divest matter of all its qualities; +strip it of colour, of solidity, and of every other property which +has any relation to our senses, and the consequence will be its +annihilation. Our mind, then, is unperishable, but matter may, and will +perish. + +It is the same with all the other faculties of our soul when compared +with the most essential properties of matter. As the mind wills and +commands, so the body obeys in every thing within its power. The +mind forms, at pleasure, an intimate union with any object; neither +distance, magnitude, nor figure, can obstruct this union, when the mind +wills it, it is effected in an instant. The body can form no union; +whatever touches it too closely injures it; it requires a long time in +order to approach another body; it every where meets with resistance, +and obstacles, and from the smallest shock its motion ceases. Is will +then nothing more than a corporeal movement; and is contemplation but a +simple contact? How could this contact take place upon a remote object +or abstracted subjects? How could this movement be accomplished in an +indivisible instant? Is it possible to have a conception of motion +without having a conception of space and time? Will, therefore, if it +be a motion, is not a material one; and if the union of the mind with +its object be a contact, it is effected at a distance: and is not this +contact a penetration? qualities which are absolutely opposite to those +of matter, and which of consequence can only belong to the immaterial +being. + +But I fear I have already dwelt too long on a subject which, by many, +may be considered as foreign to our purpose; and it might be asked, +"Ought Metaphysical Considerations on the Soul to find a place in a +System of Natural History?" Were I conscious of abilities equal to +the discussion of a topic so exalted, this reflection, I must own, +would have little weight with me; and I have contracted my remarks +only because I was afraid I should not be able to comprehend a subject +so enlarged and so important in its full extent. Why retrench from +the Natural History of Man the history of his noblest part? Why thus +preposterously debase him; by considering him merely as an animal, +while he is of a nature so different, and so superior, to that of +the brutes, that those must be immersed in ignorance like the brutes +themselves who ever thought of confounding them. + +Man, as to the material part of his existence, certainly bears a +resemblance to other animals, and in comprehending the circle of +natural beings there is a necessity for placing him in the class of +animals. Nature, however, has neither classes nor species; it contains +only individuals. These species and classes are nothing but ideas which +we have ourselves formed and established, and though we place man in +one of such classes we do not change his being; we do not derogate from +his dignity; we do not alter his condition. In a word, we only place +him at the head of those who bear a similitude to him in the material +part of his being. + +In comparing man with the animal we find in both an organized body, +senses, flesh, blood, motion, and a multitude of other resemblances. +But these resemblances are all external, and not sufficient to justify +a decision, that the human and the animal natures are similar. In +order to form a proper judgment of the nature of each we ought to +have as distinct a knowledge of the internal qualities of an animal +as we have of our own. As the knowledge of what passes within animals +is impossible to be attained, and as we know not of what order and +kind its sensations may be, in relation to those of man, we can only +judge from a comparison of the effects which result from the natural +operations of both. + +Let us, then, take a view of these effects; and, while we admit of +all the particular resemblances, limit our investigation to the most +general distinctions. It will be allowed, that the most stupid man is +able to manage the most acute animal; he governs it, and renders if +subservient to his purposes; and this, not so much on account of his +strength or skill as by the superiority of his nature, and from his +being possessed of reason, which enables him to form a rational system +of action and method, by which he compels the animals to obey him. +The strongest and most acute animals do not give law to the inferior, +nor hold them in servitude. The stronger, it is true, devour the +weaker, but this action implies no more than an urgent necessity, or +a rage of appetite; qualities very different from that which produces +a series of actions, all tending to the same end. Did animals enjoy +this faculty, should we not see some of them assume dominion over +others, and oblige them to furnish their food, to watch over them, and +to attend them when sick or wounded? Now, throughout the creation of +animals, there is no vestige of such subordination, no appearance that +one of them knows, or is sensible of, the superiority of his own nature +over that of others. It follows, then, that they must all be considered +as of one nature, and that the nature of man is not only highly +superior to that of the brute, but also entirely different from it. + +Man, by outward signs, indicates what passes within him; he +communicates his sentiments by speech, which is a sign common to the +whole human species. The savage and the civilized man have the same +powers of utterance; both speak naturally, and so as to be understood. +No other animal is endowed with this expression of thought; nor is that +defect owing, as some have imagined, to the want of proper organs. +Anatomists have found the tongue of an ape to be as perfect as that +of a man. The ape, therefore, if he had thought, would have speech, +and if its thoughts had aught analogous to ours, this speech would +have an analogy to ours also. Supposing its thoughts were peculiar to +its species, it still would hold discourse with those of its kind, a +circumstance of which we should have heard had it been endowed with the +powers of speech. So far then is the ape from having any thought like +ours, that it has not even any order of thoughts of its own. As they +express nothing by combined and settled signs, they of consequence are +void of thought, or at most have it in a very small degree. + +That it is from no organical defect animals are denied the gift of +speech is plain, as several species of them may be taught to pronounce +words, and even repeat sentences of some length. Perhaps many others +might be found capable of articulating particular sounds[AG]; but +to make them conceive the ideas which such sounds denote is an +impracticable task. They seem to repeat and articulate merely as an +echo, or an artificial machine. It is not in the mechanical powers, or +the material organs, but in the intellectual faculties, that they are +deficient. + +[AG] Leibnitz mentions a dog which had been taught to pronounce several +German and French words. + +As all language supposes a chain of thought, it is on that account +that brute animals have no speech, for even allowing something in +them which resembles our first apprehensions, our most gross and +mechanical sensations, they still will be found incapable of forming +that association of ideas which can alone produce reflection; and in +this consists the essence of thought. To this inability of connecting +and separating ideas it is that they are destitute of thought and +speech, as also that they neither can invent nor improve any thing. +Were they endowed with the power of reflection, even in the most +subordinate degree, they would be capable of making some kind of +proficiency, and acquire more industry; the modern beaver would build +with more art and solidity than the ancient; and the bee would daily +be adding new improvements to its cell; for if we suppose this cell as +perfect already as it can be, we ascribe to the insect an intelligence +superior to our own; by which it could discern at once the last degree +of perfection to which its work might be carried, while we ourselves +are for ever in the dark as to this degree, and stand in need of much +reflection, time, and practice, in order to perfect even one of our +most trivial arts. + +Whence can arise the uniformity that is in all the works of animals? +Why does each species invariably perform the same actions in the same +manner? And why does not one individual perform them better or worse +than another? Can there be a stronger proof that their operations are +merely the effects of mechanism and materiality? If they possessed +the smallest spark of that light which is inherent in mankind, their +works would display variety at least, if not perfection, and one +individual would, in its performance, make some little difference from +what another had done. But this is far from being the case. One plan +of action is common to the whole species, and whoever would attribute +a mind or soul to animals, must of necessity allow but one to each +species, of which each individual would be an equal partaker, and as +thereby it would be divisible, it would consequently be material, and +of a nature widely different from ours. + +Why, on the other hand, are the productions and performances of men +so various, and so diversified? Why is a servile imitation more +troublesome to us than an original design? It is because our souls are +our own, and independent of any other, and because we have nothing in +common with our species but the matter which forms our body, and in +which our resemblance to brute animals is confined. + +Were internal sensations dependent on corporeal organs, should we +not see as remarkable difference in the works of animals of the same +species as in those of men? Would not those which were the most happily +organized, build their nests and contrive their cells in a manner +more solid, elegant, and commodious? And if any individual possessed +a superior genius, would it not take an opportunity to manifest that +superiority in its actions? But nothing of this kind has ever happened, +and therefore the corporeal organs, however perfect or imperfect, +have no influence on the nature of the internal sensations. Hence we +may conclude, that animals have no sensations of this kind; that such +sensations have no connection with matter, no dependence in their +nature on the texture of corporeal organs, and that of consequence +there must be a substance in man different from matter, which is the +subject and the cause that produces and receives those sensations. + +But these proofs of the immateriality of the human mind may be carried +still farther. In all the works of nature there are imperceptible +gradations maintained. This truth, which in no other instance admits +of exception, is here expressly contradicted. Between the faculties of +man and those of the most perfect animal the distance is infinite; an +evident proof that man is of a different nature from the brute species, +and that of himself he forms a distinct class, between which and that +of animals there is an immense chasm. If man belonged to the class +of animals, there would be a certain number of beings in nature less +perfect than man, and more perfect than beast, in order to complete +the gradation from a man to the monkey. But this is not the case; the +transition is immediate from the thinking being to the material being; +from intellectual faculties to mechanical powers; from order and design +to blind motion; from reflection and choice to sensual appetite. + +Enough has been here advanced to demonstrate the excellence of our +nature, and of the immense distance which the bounty of the Creator has +placed between man and the brute. The former is a rational being, the +latter a being devoid of reason. And as there is no medium between the +positive and the negative, between the rational and irrational being, +it is evident that man is of a nature entirely different from that of +the animal; that all the resemblance he bears to it is merely external; +and that to judge of him by this resemblance, is wilfully to shut our +eyes against that light, by which we ought to distinguish truth from +falsehood. + +Having thus considered man as to his internal properties, and proved +the immateriality of his soul; we shall now proceed to examine his +external part, and give the history of his body. We have already traced +him from his formation to his birth, and after taking a view of the +different ages of his life, we shall conduct him to that period when he +must be separated from his body, and then resign him to the common mass +of matter to which he belongs. + + + + +CHAPTER II. + +OF INFANCY. + + +Nothing can give us a more striking idea of imbecility, than the +condition in which an infant appears on its first entrance into the +world. Incapable of making use of its organs, or senses, the infant is +in want of every assistance. It is an image of pain and misery; it is +more helpless than the young of any other animal; it seems as if every +moment would finish its doubtful existence; it can neither move nor +support itself; hardly has it strength enough to exist or announce, by +its cries, the sufferings it experiences; as if nature chose to apprise +it, that it was born to suffer, and that it has obtained a place among +the human species to partake of its infirmities and sorrows. + +Let us not disdain to consider that state through which we have all +passed; let us view human kind in the cradle; let us enquire by what +degrees this delicate machine, this new-born and hardly existing body, +acquires motion, consistency, and strength. + +The infant at its birth comes from one element into another. On +emerging from its watery residence in the womb, it becomes exposed +to the air, and instantly experiences the impressions of that active +fluid. The air acts upon the olfactory nerves and upon the organs of +respiration, and thereby produces a shock, a kind of sneezing which +expands the chest, and allows the air a passage into the lungs; the +vesicles of which it dilates, and the air remaining for some time +becomes warm and rarified to a certain degree; after which this spring +of the fibres thus dilated re-acts upon this light fluid, and expels +it from the lungs. Instead of undertaking to explain the causes of +the alternate motion of respiration, we shall confine ourselves to an +elucidation of its effects. This function is essential to the existence +of man and of several species of animals. It is by respiration that +life is preserved; and when it is once begun, it never ceases till +death. Yet there is reason to believe that the foramen ovale is not +closed immediately after the birth; and of consequence a part of +the blood may continue to pass through that aperture. All the blood +cannot, therefore, at first have a communication with the lungs; and +it is probable a new-born child might sustain a privation of air for +a considerable time without losing its existence. Or at least the +possibility of this, I once seemingly confirmed fey an experiment +upon some young dogs. I put a pregnant bitch, of the large greyhound +species, just as she was about to litter, into a tub filled with warm +water, where after fastening her in such a manner that the lower parts +were covered with some water, she brought forth three puppies, which +were accordingly received into a liquid as warm as they had left. +After washing them in this water, I removed the puppies, without giving +them time to breathe, into a smaller tub filled with warm milk; I chose +milk in order that they might receive nourishment if they required +it. In this milk they were kept immersed above half an hour: and when +taken out they were all found alive. They began to breathe, and to +discharge some moisture by the mouth. Having allowed them to respire +for half an hour, I again put them into warm milk, and left them a +second half-hour; at the expiration of which two of them were taken +out vigorous and seemingly no wise incommoded, but the third appeared +rather in a languishing state; this I caused to be carried to the +mother, which by this time had produced, in the natural way, six other +puppies; and though it had been brought forth in water and had lived +in milk one half hour before, and another after it had breathed, it +yet received so little injury from the experiment, that it presently +recovered and was as strong and lively as the rest of the litter. After +allowing the other two about an hour to breathe, I put them once more +into the warm milk, in which they remained another half hour. Whether +they swallowed any of this liquor or not is uncertain; but on being +taken out they appeared nearly as vigorous as ever. After being carried +to the mother, however, one died the same day; but whether by any +accident, or by what it had suffered while immersed in the liquid, and +deprived of air, I could not determine. The other lived, as well as the +first, and both throve equally with those which had not gone through +the same trials. This experiment I never carried farther; but I saw +enough to convince me that respiration is less necessary to a new-born, +than to a grown animal; and that it might be possible, with proper +precautions, to keep the foramen ovale from being closed, and thus +produce excellent divers, and different kinds of amphibious animals, +which might live equally in air or in water. + +The air, on its first admission into the lungs, generally meets with +some obstacle, occasioned by a liquid collected in the wind-pipe. This +obstacle is more or less great, in proportion as the liquid is more +or less viscous. At its birth, however, the infant raises its head, +which before reclined on its breast, and by this movement the canal of +the wind-pipe is lengthened, the air obtains a place, and forces the +liquid into the lungs: and by dilating the bronchia, it distributes +over their coats the mucous substance which opposes its passage. The +superfluity of this moisture is presently dried up by the renewal of +the air; or, if the infant is incommoded by it, it coughs, and at +length relieves itself by expectoration, which, as it has not yet the +strength to spit, is seen to flow from the mouth. + +As we remember nothing of what happened to us at this period, it is +impossible to determine what feelings the impression of air produces +in a new-born infant. Its cries, however, the instant it first draws +breath, are pretty certain signs of the pain it feels from the action +of the air. Till the moment of its birth, the infant is accustomed to +the mild warmth of a tranquil liquid; and we may suppose, that the +action of a fluid, whose temperature is unequal, gives too violent a +shock to the delicate fibres of its body. By warmth and by cold it +seems to be equally affected; in every situation it complains, and pain +appears to be its first, its only sensation. + +For some days after they are brought into the world, most animals +have their eye-lids closed. Infants open them the moment of their +birth, but they are fixed and dull; they want that lustre which they +afterwards acquire; and when they move, it is rather an accidental +roll than an act of vision. The pupil of the eye is seen to dilate, or +contract, in proportion to the quantity of light it receives, yet is +incapable of distinguishing objects, because the organs of vision are +still imperfect; the tunica cornea, or horny tunicle is wrinkled, and +perhaps the retina is also too soft to receive the images of external +objects, and admit the sense of seeing. + +The same remark is equally applicable to the other senses; they have +not acquired that consistency which is necessary to their operations; +and even when they have, a long time must elapse before the sensations +of the infant can be just and complete. The senses are so many +instruments which we must learn to employ. Of these sight, which seems +to be the noblest and the most admirable, is also the most uncertain +and delusive; and were its effects not every moment corrected by the +testimony of touching we should constantly be misled and draw false +conclusions. This sense of touching is the measure and criterion of +all the others; it alone is essential to the animal's existence; and +is alone diffused universally over its body. Yet, even this sense, +in an infant just born, is imperfect; by its cries, indeed, it gives +indication of pain; but it has no expression to denote pleasure. It +is forty days before it begins to smile; about the same time also it +begins to weep; its former expressions of pain being unaccompanied with +tears. On the countenance of a new born infant there appears no vestige +of the passions, the features of the face not having acquired that +consistence and form which are necessary for expressing the sentiments +of the soul. All the other parts of its body are alike feeble and +delicate; its motions are unsteady and uncertain; it is unable to +stand upright; its legs and thighs are still bent, from the habit it +contracted in the womb; it has not strength enough to stretch forth its +arms or to grasp any thing with its hands; and, if abandoned, it would +remain on its back, without being able to turn itself. + +From all which it appears, that the pain felt by infants soon after +their birth, and which they express by crying, is a sensation merely +corporeal, similar to that of other animals, who also cry the minute +they are brought forth; as also, that the mental sensations do not +begin to manifest themselves till forty days have elapsed; smiling +and weeping being produced by two internal sensations, which both +depend on the action of the mind. The former is the effect of an +agreeable emotion, which can only arise from the sight, or resemblance +of an object known, beloved, and desired; the latter is that of a +disagreeable impression, compounded of sympathy, and anxious concern +for ourselves; both imply a certain degree of knowledge, as well as an +ability to compare, and to reflect. Smiles and tears, therefore, are +signs peculiar to the human species, for expressing mental pleasure or +pain; while cries, and the other signs of bodily pain and pleasure, are +common to man, and to the greatest part of the animal creation. + +But let us return to the material organs and affections of the +body. The size of an infant born at the full time, is usually about +twenty-one inches; this is not without exception, some falling short +of and others exceeding this measurement. In children of twenty-one +inches, the breast, measured by the length of the sternum, is nearly +three inches; and in those of fourteen, only two inches. At nine +months, the foetus generally weighs from twelve to fourteen pounds. +The head is large in proportion to the rest of the body; but this +disproportion gradually wears off as the size of the child increases. +Its skin is very soft, and from its transparency, by which the blood +beneath appears, it is also of a reddish cast. It is even pretended, +that those children whose skins are the most red when born, will +afterwards be the fairest, and the most beautiful. + +The form of the body and the members of a new born infant, are by no +means perfect: all the parts are too round, and even when the child +is in good health, they seem swelled. At the end of three days, +there generally appears a kind of jaundice; and at this time there +is generally milk in the breasts of the infants, which is squeezed +out with the fingers. The superfluous juices, and the swelling of the +different parts diminish by degrees, as the child increases in growth. + +In some children just born, the brain-pan may be observed to palpitate; +and in all, the action of the sinuses, or arteries of the brain, may be +felt at this place. Over this aperture is formed a kind of scurf, which +is sometimes very thick, and must be rubbed with brushes in proportion +as it begins to dry. This matter seems to have some analogy with that +of the horns of some animals, which also derive their origin from an +aperture of the skull, and from the substance of the brain. We shall +hereafter take an opportunity to shew, that the extremities of the +nerves become solid by being exposed to the air, and that it is this +nervous substance produces claws, nails, horns, &c. + +The fluid contained in the amnios leaves a viscous, whitish matter upon +the infant, which is sometimes so adhesive, that it must be diluted +with some mild liquid before it can be removed. In this country we +never wash the infant but in warm water; yet there are whole nations, +who inhabit climates much more severe than ours, that plunge their +children into cold water the minute they are born, without their +suffering the least injury. The Laplanders are even said to leave their +infants in snow, till by the cold their respiration is nearly stopped, +and then plunge them into a bath of warm water. They are treated thus +roughly thrice every day during the first year, and afterwards as often +every week, do they undergo an immersion in cold water. The people of +the North are persuaded that the practice of cold bathing renders men +more healthy and robust; and it is for this reason they enure their +progeny to it from their birth. The truth is, we are ignorant with +the extent of what our body is capable of suffering, acquiring, or +losing by the power of habit. The Indians in the isthmus of America, +for example, receive no injury from plunging into cold water when in +a sweat; and as the most speedy remedy for intoxication, the women +throw their husbands into the river when they are drunk; the minute +after delivery, mothers scruple not to bathe in cold water with their +infants, and yet dangerous as we should consider this practice, these +women are rarely known to die in child-bearing. + +A few minutes after birth the infant discharges urine, and this +generally when it feels the heat of the fire: and sometimes also the +meconium or excrement which have been collected in the intestines +during its residence in the matrix. This last evacuation is not always +performed so soon, but if it does not happen in the course of the first +day, the child is often affected with a pain in the bowels; in which +case methods are taken to facilitate the discharge. The meconium is +black, and when the infant is effectually eased of it, the subsequent +stools are of a whitish cast. This change generally happens on the +second or third day, and then the excrement becomes more foetid than +the meconium; a proof that the bile and other bitter humours of the +body begin to intermix with it. This fact tends to support our former +remark, that the foetus did not receive any food by its mouth, but +received all its nourishment by absorption. + +The infant is allowed time to throw off the slime and meconium, which +are in its bowels and intestines, before it is allowed to suck. As +these substances might sour the milk, and produce bad effects, it is +first made to swallow a little wine and sugar, in order to fortify the +stomach, and to procure such evacuations as may be necessary to prepare +it for receiving and digesting its food; nor ought it to receive the +breast till 10 or 12 hours after the birth. + +Hardly has the infant left the womb of its mother, and enjoyed the +liberty of extending its limbs, when it is again put into a more cruel +confinement. The head of the helpless infant is fixed to one position; +its arms and legs put in strict bondage, and it is laced with bandages +so strait as not to be able to move a single joint. Well is it when the +compression is not so great as to obstruct the respiration, or that +the midwife has taken the precaution to lay it upon its side, that the +natural moisture may emit of itself from the mouth, since it is denied +the power of turning its head in order to facilitate this emission. +Do not then those nations act more wisely than we who cover or clothe +their children without shackling them in swathing-bands? the Siamese, +the Japanese, the Indians, the Negroes, the Savages of Canada, of +Virginia, or Brazil, and almost all the inhabitants of South America, +lay their infants naked upon a suspended bed of cotton or put them into +their cradles lined with fur. Those practices are certainly liable to +less inconveniences than ours. In swaddling a child, it is impossible +but the restraint must give it uneasiness; and the efforts it makes to +disentangle itself have a greater tendency to injure the form of the +body, than any position it might assume was it left at full liberty. +Swathing-bands may be compared to stays, which young girls are made to +wear in order to preserve their shapes, but which nevertheless occasion +more diseases and deformities than they are supposed to prevent. + +If the efforts which children make for liberty, when confined in the +swaddling-clothes, are hurtful, the inaction in which they are held by +it, is perhaps still more so. Want of exercise naturally retards the +growth of their limbs, and diminishes the strength of their bodies; +and of consequence such children as enjoy the liberty of moving at +pleasure, must be the most vigorous. It was for this reason that the +ancient Peruvians gave their infants the full freedom of their arms in +a swathing-bag; afterwards, as their children grew, they put them up to +the middle in a hole dug in the earth, and lined with linen; by this +method they had their arms free, and could move their heads and bend +their bodies, without falling or hurting themselves. So soon as they +were able to step, they were presented with the breast, at a little +distance, as an incentive for them to walk. The children of Negroes are +often exposed to much greater fatigues, in order to come at the nipple, +they cling round one of their mother's haunches with their legs, and +support themselves without any assistance from her; seizing the breast +they continue to suck in perfect safety, notwithstanding she is all the +while in motion, or at work. These children begin to walk, or rather +creep on their knees and hands, in the second month; and this exercise +qualities them for running afterwards in this manner, almost as nimble +as they do upon their feet. + + +_END OF THE THIRD VOLUME._ + + +T. Gillet, Printer, Wild Court. + + + + + * * * * * + + + + +Transcriber's note: + +All paragraphs split by illustrations were rejoined. + +All obvious typographical errors were corrected. + +In the Table of Contents, Chapter VI's starting page was corrected +to 81. + +On page 203, the word sospetare was changed to sospettare. + +Chapter XI (p. 260) was mislabeled as "IX" and was corrected. + +Likewise, Chapter II (page 334) was mislabeled "III" and +was corrected. + +Otherwise, all text is as presented in the printed version. + + + +***END OF THE PROJECT GUTENBERG EBOOK BUFFON'S NATURAL HISTORY, VOLUME III +(OF 10)*** + + +******* This file should be named 45639-8.txt or 45639-8.zip ******* + + +This and all associated files of various formats will be found in: +http://www.gutenberg.org/dirs/4/5/6/3/45639 + + + +Updated editions will replace the previous one--the old editions +will be renamed. + +Creating the works from public domain print editions means that no +one owns a United States copyright in these works, so the Foundation +(and you!) can copy and distribute it in the United States without +permission and without paying copyright royalties. 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