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diff --git a/old/63416-0.txt b/old/63416-0.txt deleted file mode 100644 index 3599455..0000000 --- a/old/63416-0.txt +++ /dev/null @@ -1,8218 +0,0 @@ -Project Gutenberg's Rust, Smut, Mildew, & Mold, by Mordecai Cubitt Cooke - -This eBook is for the use of anyone anywhere in the United States and most -other parts of the world 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. If you are not located in the United States, you'll have -to check the laws of the country where you are located before using this ebook. - -Title: Rust, Smut, Mildew, & Mold - -Author: Mordecai Cubitt Cooke - -Release Date: October 9, 2020 [EBook #63416] - -Language: English - -Character set encoding: UTF-8 - -*** START OF THIS PROJECT GUTENBERG EBOOK RUST, SMUT, MILDEW, & MOLD *** - - - - -Produced by deaurider, Barry Abrahamsen, and the Online -Distributed Proofreading Team at https://www.pgdp.net (This -file was produced from images generously made available -by The Internet Archive) - - - - - - - - - - RUST, SMUT, MILDEW, & MOULD. - - - - ------------------------------------------------------------------------- - - - - - LONDON: - GREAT QUEEN STREET, - LINCOLN’S-INN FIELDS, W.C. - - - - ------------------------------------------------------------------------- - - -[Illustration: - - Plate VII. - W. West imp. -] - - ------------------------------------------------------------------------- - - - Rust, Smut, Mildew, & Mould. - - - --------------------- - - - - AN INTRODUCTION TO THE STUDY - - - OF - - - MICROSCOPIC FUNGI. - - - - - BY - - - M. C. COOKE, - - AUTHOR OF “A PLAIN AND EASY ACCOUNT OF BRITISH FUNGI,” “INDEX - FUNGORUM BRITANNICORUM,” “A MANUAL OF BOTANIC TERMS,” - “A MANUAL OF STRUCTURAL BOTANY,” ETC. - - - - - Third Edition, - WITH NEARLY 300 FIGURES BY J. E. SOWERBY. - - - - - LONDON: - ROBERT HARDWICKE, 192, PICCADILLY. - 1872. - - ------------------------------------------------------------------------- - - - - - BY THE SAME AUTHOR. - -THE BRITISH FUNGI: A Plain and Easy Account of British Fungi: with -especial reference to the Esculent and other Economic Species. -Illustrated with Coloured Plates of 40 Species. 2nd Edition. Fcap. 8vo., -price 6s. - -“The author is a thorough mycophagist, well acquainted with the peculiar -features by which the most remarkable of the edible kinds of Fungi may -be known.”—GARDENERS’ CHRONICLE. - -“A very readable volume upon the lowest and least generally understood -race of plants. For popular purposes the work could not have been better -done.”—ATHENÆUM. - - ------- - -INDEX FUNGORUM BRITANNICORUM: A Complete List of Fungi found in the -British Islands to the Present Date. Arranged so as to be applicable -either as a Check-List or for Herbarium Labels. Royal 8vo., price 2s. -6d. - - Also the same Work, printed on only one side, for Herbarium Labels. - Part I. HYMENOMYCETES, 1s. Part II. GASTEROMYCETES, CONIOMYCETES, - and HYPHOMYCETES, 1s. Part III. ASCOMYCETES, 1s. - - -------------- - - London: ROBERT HARDWICKE, 192, Piccadilly. - - - - ------------------------------------------------------------------------- - - - - - PREFACE TO SECOND EDITION. - - -THE first edition of this Work having for some time been out of print, -and the demands of the public encouraging the publisher to proceed with -a new edition, I have added, in a second Appendix, descriptions of all -the species discovered in Britain since 1865, so far as they relate to -the Orders included in this volume. The success which has attended the -sale of this Work, and the number of fresh observers it has brought into -the field, has greatly tended to the necessity for a second Appendix. A -larger number of observers, over a still more extended area, will, it is -hoped, add further to our list; by increasing the number of known -species. Hitherto one great cause of the paucity of students of Fungi in -this country, especially of the Microscopic forms, has been the want of -text-books on the subject, containing descriptions of the species, with -figures illustrative of the genera. Although this little volume only -partly supplies that want, by including the species found on living -plants alone, it has already proved of service; this and its companion -volume, “Introduction to British Fungi,” being (with but one exception) -the only books on Fungi which have passed into a second edition in this -country; a fact which appears to prove that they have succeeded in -furnishing a desideratum, and in giving an impetus to the study. It is -hoped that similar results will follow the publication of this new -edition. - - M. C. COOKE. - - ------------------------------------------------------------------------- - - - - - CONTENTS. - - - CHAP. PAGE - - I. CLUSTER-CUPS 1 - - II. SPERMOGONES 22 - - III. DI-MORPHISM 33 - - IV. MILDEW AND BRAND 45 - - V. COMPLEX BRANDS 67 - - VI. SMUTS 77 - - VII. COMPLEX SMUTS 90 - - VIII. RUSTS 95 - - IX. RUSTS (continued) 110 - - X. WHITE RUSTS 124 - - XI. MOULDS 138 - - XII. WHITE MILDEWS OR BLIGHTS 162 - - XIII. SUGGESTIONS 179 - - APPENDIX, CLASSIFICATION, AND 189 - DESCRIPTIONS OF FUNGI CONTAINED - IN THIS VOLUME - - APPENDIX II. 223 - - Index 239 - - ------------------------------------------------------------------------- - - - - - MICROSCOPIC FUNGI. - - ------- - - - - - CHAPTER I. - - _CLUSTER-CUPS._ - - -IN these latter days, when everyone who possesses a love for the -marvellous, or desires a knowledge of some of the minute mysteries of -nature, has, or ought to have, a microscope, a want is occasionally felt -which we have essayed to supply. This want consists in a guide to some -systematic botanical study, in which the microscope can be rendered -available, and in which there is ample field for discovery, and ample -opportunity for the elucidation of facts only partly revealed. Fungi, -especially the more minute epiphyllous species, present just such an -opportunity as many an ardent student would gladly take advantage of; -one great obstacle to the pursuit being hitherto found in the absence of -any hand-book to this section of the British Flora, embracing the -emendations, improvements, and additions of the past twenty-seven years -(the period at which the fifth volume of the “English Flora” made its -appearance). It would be incompatible with our object, and beyond our -limits, to introduce an entire mycological flora to our readers in these -pages; but we hope to communicate such information as will serve to -prepare the way still more for such an additional Flora, should it ever -be produced, and render the demand still wider and more general for such -an extension of our botanical literature. It is true that one work has -of late years issued from the press on this subject, but notwithstanding -its utility to scientific men as a record of species, it is practically -useless to those we address, from the absence of all specific -descriptions of microscopic fungi. - -Let not the reader imagine, from what we have just stated, that it is -our intention to burden him with a dry series of botanical descriptions; -as much of this as we deem essential to render the book available to the -botanical student, we have preferred to add in the form of an Appendix. -Useful as these may be to some, we hope to be enabled to furnish for -others something more; and although we at once disclaim any intention of -including all the microscopic, or even the epiphytal fungi, in our -observations, yet we trust, by a selection of common and typical species -for illustration, and by an adherence to certain well-defined groups and -sections, to demonstrate that the microscopist will find an eligible -field for his observations in this direction, and the botanical student -may gain some knowledge of their generic and specific distinctions. - -It is exceedingly difficult to give a logical definition of what -constitutes a fungus. It is no less difficult to furnish a popular -description which shall include all and nothing more. If, for example, -we particularize the spots and markings on the leaves and stems of -herbaceous plants, so commonly met with from early spring till the fall -of the last leaf, and even amongst the dead and decaying remains of the -vegetation of the year, we may include also such spots and marks as -result from insect depredations or diseased tissue. It is not always -easy, with a cursory observation under the microscope, to determine -whether some appearances are produced by fungi, insects, or organic -disease: experience is the safest guide, and until we acquire that we -shall occasionally fail. - -If we take a stroll away from the busy haunts of men, though only for a -short distance,—say, for example (if from London), down to New -Cross,—and along the slopes of the railway cutting, we shall be sure to -find the plant called the goatsbeard (_Tragopogon pratensis_) in -profusion. In May or June the leaves and unopened involucres of this -plant will present a singular appearance, as if sprinkled with -gold-dust, or rather, being deficient in lustre, seeming as though some -fairy folk had scattered over them a shower of orange-coloured chrome or -turmeric powder. Examine this singular phenomenon more closely, and the -poetry about the pixies all vanishes; for the orange powder will be seen -to have issued from the plant itself. A pocket lens, or a Coddington, -reveals the secret of the mysterious dust. Hundreds of small orifices -like little yellow cups, with a fringe of white teeth around their -margins, will be seen thickly scattered over the under surface of the -leaves. These cups (called _peridia_) will appear to have burst through -the epidermis of the leaf and elevated themselves above its surface, -with the lower portion attached to the substratum beneath. In the -interior of these cup-like excrescences, or _peridia_, a quantity of the -orange-coloured spherical dust remains, whilst much of it has been shed -and dispersed over the unoccupied portions of the leaves, the stems, and -probably on the leaves of the grass or other plants growing in its -immediate vicinity. These little cups are fungi, the yellow dust the -spores,[1] or ultimate representatives of seed, and the epiphytal plants -we have here found we will accept as the type of the group or order to -which we wish to direct attention (Plate I. figs. 1-3). - - -[Illustration: - - Plate I. - W. West imp. -] - - -Footnote 1: - - Protospores they should be called, because, in fact, they germinate, - and on the threads thus produced the true spores, or fruit, are borne. - -Amongst the six families into which fungi are divided, is one in which -the spores are the principal feature, as is the aurantiaceous dust in -the parasite of the goatsbeard. This family is named _Coniomycetes_, -from two Greek words, meaning “dust-fungi.” This group or family -includes several smaller groups, termed orders, which are analogous to -the natural orders of flowering plants. Without staying to enumerate the -characteristics of these orders, we select one in which the spores are -enclosed in a distinct peridium, as in our typical plant they are -contained within the cups. This order is the _Æcidiacei_, so called -after _Æcidium_, the largest and most important of the genera included -within this order. - -The _Æcidiacei_ are always developed on living plants, sometimes on the -flowers, fruit, petioles, or stems, but most commonly on the leaves: -occasionally on the upper surface, but generally on the inferior. The -different species are distributed over a wide area; many are found in -Europe and North America, some occur in Asia, Africa, and Australia. -When the cryptogamic plants of the world shall have been as widely -examined and as well understood as the phanerogamic plants have been, we -shall be in a better position to determine the geographical distribution -of the different orders of fungi. In the present incomplete state of our -knowledge, all such efforts will be unsatisfactory. - -But to return to the goatsbeard, and its cluster-cups. The little fungus -is called _Æcidium tragopogonis_, the first being the name of the genus, -and the last that of the species. Let us warn the young student against -falling into the error of supposing because in this, and many other -instances, the specific name of the fungus is derived from the plant, or -one of the plants, upon which it is found, that therefore the species -differs with that of the plant, and that, as a rule, he may anticipate -meeting with a distinct species of fungus on every distinct species of -plant, or that the parasite which he encounters on the living leaves of -any one plant is _necessarily_ specifically distinct from those found on -all other plants. One species of _Æcidium_, for instance, may hitherto -have been found only on one species of plant, whereas another _Æcidium_ -may have been found on five or six different species of plants. The -mycologist will look to the specific differences in the parasite without -regard to the identity or distinctness of the plant upon which it is -parasitic. - -Before the _Æcidium_ breaks through the epidermis, the under surface of -the leaves of the goatsbeard will appear to be covered with little -elevations or pustules, paler at the apex; these soon become ruptured, -and the fungus pushes its head through the opening, at the same time -bursting by radiating fissures. The teeth thus formed resemble those of -the peristome of some mosses. All around the orifice of the peridium the -teeth become recurved, and the orange spores are exposed, crowded -together within. At first, and while contained within the peridium, -these spores are concatenate or chained together, but when dispersed -they are scattered singly about the orifice, often mixed with the -colourless cells arising from the partial breaking up of the teeth of -the peridium. - -Let us pause for a moment in our examination of the individual cups, to -ascertain their manner of distribution over the leaves. In this instance -they are scattered without any apparent order over the under surface, -but generally thickest towards the summit of the leaves; occasionally a -few are met with on the upper surface. Sometimes two or three touch at -the margins, but we have never met with them truly confluent; generally -there is a space greater than the width of the cups around each, the -stratum or subiculum from whence they arise is scarcely thickened, and -there are no spots or indications on the opposite surface. If a leaf be -taken fresh and the cuticle stripped off, which it will sometimes do -very readily, the orifices through which the _Æcidium_ has burst will -appear in irregular holes. If a section be made of one or two of the -fungi _in situ_, they will be seen to spring from beneath the cuticle, -the peridium to be simple, and rounded at the base, the spores clustered -at the bottom, and the fringe to be a continuation of its cellular -substance. - -The spores in this species are orange, subglobose, sometimes angular, -and indeed very variable both in size and form, though the majority are -comparatively large. Each of these bodies is, doubtless, capable of -reproducing its species, and if we compute 2,000 cluster-cups as -occurring on each leaf, and we have found half as many more on an -ordinary-sized leaf, and suppose each cup to contain 250,000 spores, -which again is below the actual number, then we shall have not less than -five hundred millions of reproductive bodies on one leaf of the -goatsbeard to furnish a crop of parasites for the plants of the -succeeding year. We must reckon by millions, and our figures and -faculties fail in appreciating the myriads of spores which compose the -orange dust produced upon one infected cluster of plants of -_Tragopogon_. Nor is this all, for our number represents only the actual -protospores which are contained within the peridia; each of these on -germination may produce not only one but many vegetative spores, which -are exceedingly minute, and, individually, may be regarded as embryos of -a fresh crop of cluster-cups. And this is not the only enemy of the kind -to which this unfortunate plant is subject, for another fungus equally -prolific often takes possession of the interior of the involucre wherein -the young florets are hid, and converts the whole into a mass of -purplish black spores even more minute than those of the _Æcidium_, and -both these parasites will be occasionally found flourishing on the same -plant at the same time (Plate V. figs. 92-94). - -Naturally enough, our reader will be debating within himself how these -spores, which we have seen, are shed in such profusion, can enter the -tissues of the plants which give subsequent evidence of infection; in -fact, how the yellow dust with which the goatsbeard of to-day is covered -will inoculate the young plants of next year. If one or two of these -spores are sprinkled upon the piece of the cuticle which we have -recommended to be removed from the leaf for examination, it will be seen -that they are very much larger than the stomata or breathing-pores which -stud the cuticle: hence it is clear that they cannot gain admittance -there. There remains but one other portal to the interior of the -plant—namely, the spongioles, or extremities of the roots. Here another -difficulty arises; for the spores are as large as the cells through -which they have to pass. This difficulty may be lessened when we -remember that what are termed the spores which are discharged from the -cups are not the true spores, but bodies from which smaller seed-like -vesicles are produced; yet, even then there will be much need of an -active imagination to invent hypotheses to cover the innumerable -difficulties which would encounter their passage through the vessels of -the infected plants. The Rev. M. J. Berkeley proved many years ago that -the spores of bunt, for example, may be caused to infect all the plants -the seeds of which had been placed in contact with them; but this -affection did not necessarily accrue from the absorption of the spores, -or the ultimate sporidia produced after three or four generations. It is -possible that the granular or fluid contents of the spores may be -absorbed by the plant, and as a result of this absorption, become -inoculated with the virus, which at length breaks out in fungoid -growths. Much has been done to elucidate this mystery of inoculation, -but much also remains a mystery still. There is no doubt that the -inoculation takes place at an early age,[2] probably in the seeds of -many plants; in others it may be conveyed with the moisture to the -roots; but the spores themselves have certainly not yet been traced -traversing the tissues of growing plants. - -Footnote 2: - - Dr. de Bary has lately shown that in many similar instances the - seed-leaves are inoculated. It will be necessary to refer more - particularly to his experiments hereafter. - -If, instead of going in search of goatsbeard and its attendant fungus, -we turn our steps northward and enter one of the Highgate or Hampstead -woods, where the pretty little wood-anemone (_Anemone nemorosa_) -flourishes abundantly, and turn up the radical leaves, one by one, and -examine their under-surfaces, we shall at length be rewarded by finding -one covered with similar cluster-cups to those we have been describing -as occurring on the goatsbeard, but far less commonly. Leaf after leaf -will be found covered with the brown spots of another fungus called -_Puccinia anemones_, with which nearly every plant will be more or less -infected in the spring of the year; and at length, if we persevere, the -anemone cluster-cup (_Æcidium leucospermum_) will be our reward (Plate -I. figs. 4-6). The specific name will suggest one point of difference -between the two fungi, as in this instance the spores are white, and -somewhat elliptic. Probably this species is not common, as we have found -it but seldom, though often in search of it. A nearly allied species has -been found on _Anemones_ in gardens, having but few large teeth about -the orifice, though not constantly four, as the name would indicate (_Æ. -quadrifidum_). - -A walk through almost any wood, in the spring of the year, will reward -the mycologist with another cluster-cup (_Æcidium_), in which the -peridia are scattered over the whole surface of the leaf. This will be -found on the wood spurge, giving a sickly yellowish appearance to the -leaves, on the under surface of which it is found. By experience one may -soon learn to suspect the occurrence of parasites of this nature on -leaves, from the peculiar exhausted and unhealthy appearance which they -assume as the spores ripen, and which will spare the labour of turning -over the leaves when there are no distinct spots on the upper surface. -_Æ. Euphorbiæ_ is found on several species of _Euphorbium_ or spurge, -but we have always found it most abundantly on the wood spurge in the -Kentish woods between Dartford and Gravesend. The spores in this species -are orange, and externally it bears considerable resemblance to the -goatsbeard cluster-cup, but the spores are rather smaller and paler, the -teeth are less distinct and persistent, the subiculum is more thickened, -and the peridia are more densely crowded. - -There is another group of species belonging to the same genus of fungi -in which the arrangement of the peridia is different. One of the first -of our native wild flowers, in making its appearance after the departure -of frost and snow, is the little yellow celandine (_Ranunculus -ficaria_). - - “Ere a leaf is on the bush, - In the time before the thrush - Has a thought about her nest, - Thou wilt come with half a call, - Spreading out thy glossy breast - Like a careless Prodigal; - Telling tales about the sun - When we’ve little warmth, or none.” - -And one of the earliest parasitic fungi in spring is an _Æcidium_ which -flourishes on its glossy leaves. So common is _Æcidium ranunculacearum_ -on this species of _Ranunculus_, that it can scarcely have escaped the -eye of any one who has taken the trouble to examine the plant. It -appears in patches on the under surface of the leaves or on their -petioles, in the latter case swelling and distorting them. Sometimes -these patches are nearly circular, at others of very irregular form, and -varying in size from less than one-twelfth of an inch to half an inch in -diameter. It is found on several species of _Ranunculus_, as _R. acris_, -_bulbosus_, and _repens_, but most commonly on _R. ficaria_. The leaf is -thickened at the spot occupied by the parasite, and generally without -indication on the opposite surface. Sometimes one spot, at others -several, occur on the same leaf. The peridia are densely crowded -together, often arranged in a circinate manner, _i.e._, like a -watch-spring, or the young frond of a fern. The spores are orange, but -slightly varying in tint on different species of _Ranunculus_ (Plate II. -figs. 12-14). One of the smaller clusters, when collected before the -spores are dispersed, or the teeth of the peridium discoloured, mounted -dry as an opaque object, makes a very excellent slide for an inch or -half-inch objective; and the same may be said of many others of the same -genus. - -Less common than the foregoing is the species of _Æcidium_ which attacks -the violet. The sweetest of flowers as well as the earliest, in despite -both of its odour and its humility, becomes a victim to one or more of -the ubiquitous race of fungi. Thickened spots at first appear on the -leaves; the petioles, or flower stem, or even the calyx, become swollen -and distorted; and at length the cluster-cup breaks through. The spots -on the leaves upon which the peridia are scattered are yellowish, -generally larger than the clusters on the pilewort, and seldom with more -than one spot on each leaf. The peridia, or cups, are irregularly -distributed over the spots, not crowded together as in the last species; -and the teeth are large, white, and distinct. The spores are at first -orange, but at length become brownish. This species may be found in -spring, as late as June, most commonly on the dog-violet, but also on -other species of _Viola_. - -It is not a very desirable occupation to search a bed of nettles, and -turn over the individual leaves to look for minute fungi. A very pretty -_Æcidium_ is nevertheless far from uncommon in such a habitat. -Fortunately it occurs very often on the petioles of the leaves and on -the stem, distorting them very much; and in such situations flourishing, -apparently, more vigorously than when occupying the under surface of the -leaves (Plate I. fig. 10). In the latter situation the clusters of -peridia are small, seldom exceeding a dozen in a spot, but several spots -may be found on the same leaf. On the stem they are clustered around for -upwards of an inch in length, and their bright orange colour in such a -situation renders them very conspicuous objects. The peridia are always -closely packed together upon a thickened base, and offer but slight -variations from the forms already enumerated, save that they widen -slightly at the mouth, so as to become nearly campanulate. The spores -are orange, and very profuse. - -During the past summer we noticed, for the first time, a very pretty -little species of cluster-cup (_Æcidium_) on the wood sanicle (_Sanicula -Europæa_) in Darenth wood. It was far from uncommon, and we believe it -to be specifically distinct from its nearest ally, found on the earthnut -leaves, and those of some other umbelliferous plants. The little cups -are in small clusters of four or five together, on the under surface and -on the petioles; they are small, but the teeth are relatively large, -white, and distinct. The spores are of a pallid, yellowish colour, and -not so profuse as in the last species. A darker spot on the upper -surface of the leaf generally indicates their presence. This species was -found many years ago by Carmichael at Appin, and called by him _Æcidium -saniculæ_; but we find no notice of its occurrence since, though it -seems to be far from uncommon at Darenth, and probably elsewhere, should -the sanicle be common also. - -Recently we found the bedstraw cluster-cup (_Æcidium galii_) on the -great hedge bedstraw (_Galium mollugo_), and as it has not been figured -before, we have included it amongst our illustrations (Plate II. figs. -15-17). Though very insignificant when occurring on the small leaves of -the yellow bedstraw (_Galium verum_), it is a prominent object on the -above-named species. - -We received, for the first time, in July, 1864, from Mr. Gatty, student -at Winchester, a portion of a plant of _Thesium humifusum_ (which is by -no means common in Britain), covered with beautiful cluster-cups of a -species never before recorded as occurring in this country (Plate III. -figs. 50, 51) named _Æcidium Thesii_, but which is far from uncommon on -the Continent. It occurred in this instance on the Downs, in the -vicinity of Winchester. - -It is unnecessary here to refer to other allied species of _Æcidium_, -except one to be presently noticed, since we have, at the end of the -volume, enumerated and given descriptions of all the species hitherto -found in Britain. Suffice it to say that the Buckthorn cluster-cups on -the alder buckthorn (_Rhamnus frangula_), is usually very common in the -Highgate and Hornsey woods, and on the common buckthorn (_Rhamnus -catharticus_) in the neighbourhood of Dartford, in Kent. That on the -honeysuckle we have found but very rarely. On the gooseberry and -red-currant leaves, commonly in some years and rarely in others; whilst -a few of those described we have never collected. The species on -different composite plants is subject to great variation, and on most -may be found in the autumn; one variety only, on the leaves of _Lapsana -communis_, we have met with in the spring. - -Very few years ago farmers generally believed that the cluster-cups of -the berberry (_Berberis vulgaris_), were productive of mildew in corn -grown near them; this opinion even received the support of Sir J. Banks, -but no fungi can be much more distinct than those found on corn crops -and this species on the leaves of the berberry. In this instance the -cups are much elongated, and cylindrical, the clusters vary much in -size, and the spots on the upper surface of the leaf are reddish, -bright, and distinct. The teeth are white and brittle, and the orange -spores copious (Plate I. figs. 7-9). - -There are scarcely any of the epiphyllous fungi forming equally handsome -or interesting objects for low powers of the microscope, than the genus -to which attention has just been directed; and they possess the -advantage of being readily found, for that locality must be poor indeed -which cannot furnish six species during the year. We have found half of -the number of described species within little more than walking distance -of the metropolis, within a period of little more than three months, and -should be glad to hear of the occurrence of any of the rest. - -We have three species of fungi very similar in many respects to the -foregoing, but differing in others to such an extent as to justify their -association under a different genus and name. The hawthorn is a bush -familiar to all who love the “merry month of May,” but it may be that -its parasite has been unnoticed by thousands. If, for the future, our -readers will bear this subject in their minds when they stand beneath a -hawthorn hedge, they may become acquainted with clusters of singular -brown pustules on the leaves, petioles, and fruit well worthy of more -minute examination (Plate II. fig. 22). They scarcely claim the name of -cups, and their lacerated and fringed margins rather resemble the pappus -crowning the fruits of some composite plants than the cups of _Æcidium_. -The peridia are very long, and split down throughout their length into -thread-like filaments of attached cells; these gradually fall away and -break up into their component parts till but short portions remain -attached to the base of the peridia. These cells are elongated and -marked on the surface with waved lines, forming in themselves pretty -objects for a high power of the microscope (Plate II. figs. 23, 24). If -the teeth of _Æcidium_ resemble the peristome of some mosses, such as -_Splachnum_; the threads of this species of _Rœstelia_, except in not -being twisted, somewhat resemble the peristomes of other mosses of the -genus _Tortula_. The spores in this species are less conspicuous, being -of a light brown, and the whole plant, from its modest hue, may be -readily passed over without attracting attention unless occurring in -abundance. - -The leaves of pear-trees afford a second species of this genus -sufficiently distinct to commend it to our notice. Sometimes it is very -common, at others but few examples are to be met with. The clusters -occur on the under surface, and consist of half-a-dozen or less of large -peridia, pointed at the apex and swelling in the middle so as to become -urn-shaped (Plate II. figs. 20, 21). These vessels or thecæ split into -numerous threads or laciniæ, which remain united together at the apex. -Like the species already noticed, this is brown and inconspicuous except -on account of its size, for it is the largest of all that we have had -occasion to notice. - -The third species occurs on the under surface of the leaves of the -mountain-ash. The peridia are clustered on a rusty orange-coloured spot -which is visible on the upper surface (Plate II. figs. 18, 19). They are -long and cylindrical, with an evident tendency to curvature; the mouth -is serrated, but not split up into threads, as in the species found on -the hawthorn. There will often be found instead of well-developed -peridia, what at one time were regarded as abortive peridia, forming a -thickened orange or rust-coloured spot, studded with minute elevated -points. These spots are clusters of spermogones, which organs are -described in detail in our second chapter. The clusters and spores are -of a brighter reddish-brown than in either of the other species. All are -remarkably distinct, and perhaps the most curious and interesting of any -that we have passed in review. To botanists, the species found on the -hawthorn is known as _Rœstelia lacerata_, that on pear-leaves as -_Rœstelia cancellata_, and the one on the leaves of the mountain-ash as -_Rœstelia cornuta_. - -Dr. Withering observed the spore-spots on the leaves of the -mountain-ash, but was evidently puzzled to account for them. He writes -(in his Arrangement of British Plants), “The spots on the leaves of -_Sorbus aucuparia_ consist of minute globules intermixed with wool-like -fibres. On examining many of them in different states, I at length found -a small maggot in some of the younger spots, so that the globules are -probably its excrement, and the fibres, the woody fibres of the plant -unfit for its food.” We now-a-days smile at such simple and singular -conjectures. It affords evidence of the manner in which the speculations -of one generation become follies in the next. - -Only two species of cluster-cups are described in Withering’s Flora -under the genus _Lycoperdon_: one of these is now called _Æcidium -compositarum_, and is found on various composite plants; the other -includes the species found on the wood-anemone and that on the -moschatel, and also probably a species of _Puccinia_ on the wood-betony. - -To render this chapter more complete, though of less importance to the -microscopist, we may allude to the other two genera comprised within -this order. _Peridermium_ is the name of one genus which contains two -British species found on the leaves and young shoots of coniferous -trees. In this genus the peridium bursts irregularly, and does not form -cups, or horns, or fringed vessels. The most common species is found on -the needle-shaped leaves of the Scotch fir (Plate II. fig. 27), and also -on the young twigs, in the latter instance larger and more prominent -than in the former. The elongated peridia burst irregularly at their -apices without forming teeth (fig. 28). - -In the genus _Endophyllum_, as its name implies, the peridium is -imbedded within the substance of the succulent leaves. The only species -we possess is found rarely upon the common house-leek. - -We have derived much pleasure in viewing the astonishment and delight -exhibited by friends to whom we have personally communicated specimens -of the little fungi we have enumerated for examination under the -microscope; and we recommend with confidence this group of parasitic -plants, unfortunately so little known, as well worthy of the attention -of all who are interested in the minute aspects of nature, and who can -recognize the hand— - - “That sets a sun amidst the firmament, - Or moulds a dew-drop, and lights up its gem.” - - ------------------------------------------------------------------------- - - - - - CHAPTER II. - - _SPERMOGONES._ - - -IN addition to their spore-bearing spots, lichens have for some time -been known to possess other organs, termed _spermogones_, which are -probably concerned more or less in the reproductive process. The first -intimation of the existence of similar bodies in the entophytal fungi -originated with M. Unger in 1833, but it was left to Dr. de Bary and the -Messrs. Tulasne, twenty years later, to examine and determine -satisfactorily the nature and value of the spermogones of the Uredines. -It was at first believed that the smaller pustules—which sometimes -precede, and sometimes accompany, the cluster-cups and some other allied -fungi—were distinct species developed simultaneously therewith, or -members of a new genus, which, under the name of _Æcidiolum -exanthematum_, found a place in the mycologic system. - -Without staying to trace the stages through which the elucidation of -their true nature proceeded, it will suffice for our purpose to tell -what is now known of these secondary organs; to accomplish which we must -stand greatly indebted to the independent researches of Messrs. de Bary -and Tulasne. It has been demonstrated that both these bodies, namely, -the primary organs or cluster-cups, and the secondary organs or -spermogones, are developed from the same mycelium; but the value of the -latter is still undetermined. If they possess any fecundative power, the -process has not been traced; or if they are in themselves reproductive, -they have not at present been seen to germinate. Their uses, therefore, -in the economy of the parasitic plant of which they are now known to -form a part is still a mystery, and they remain valueless in the -determination of genera and species. Any speculation which might regard -them as male organs would be premature, and without support in fact. -Hitherto only some species of the genera described in the foregoing -chapter, and others belonging to genera not hitherto named, have been -ascertained to possess spermogones. Of the former are the _Rœsteliæ_, -some species of _Æcidium_, as those of _Euphorbia_, &c., and -_Peridermium Pini_. - -These spermogones are of a very simple structure—very delicate, indeed; -so much so, that they will scarcely bear preparation for demonstration. -De Bary states that they originate from plain, delicate, inarticulate -threads, about half the thickness of the mycelium (the root-like -branching fibres which form the fundamental stratum of fungoid growths), -which are developed in large quantities, and closely packed together. -These threads are compacted together so as to form an outer enveloping -integument or peridium, which is either globular or hemispherical (or in -some instances elongated), more or less immersed, and at length opening -at the apex (fig. 153) by a regularly formed minute ostiolum. The inner -wall of the peridium is covered with a thick forest of simple filaments -standing on end. From the summit of these filaments or sterigmata, the -spermatia are borne. These are either isolated or associated together in -strings or chaplets, are exceedingly minute, of an ovoid or oblong -shape, and are produced in such numbers as to fill the cavity of the -spermogone. Besides these, a viscid fluid is secreted, in which the -spermatia are immersed, and which is expelled with them from the orifice -of the peridium. According to the density of this fluid, or the -hygrometric state of the atmosphere, it appears sometimes in drops, and -sometimes oozing out in threads or cirrhi from the spermogones. To -compare minute things with gigantic, as a recent author has observed, it -resembles the lava issuing from the crater of a volcano. The colour of -this spermatiferous matter is commonly orange, but in some instances -brown, though not constantly of the same colour as the spores produced -from the same mycelium. This gelatinous substance is dissolved away from -the granular bodies which are immersed in it, by adding a little water -upon the slide on which the mass is placed for examination. The -granules, or spermatia, then exhibit those peculiar movements which have -been observed in the similar bodies in lichens, and fitly described as -“a sort of oscillating motion, as of a body attached at one extremity.” -The cause of this motion is at present uncertain, vibratile ciliæ, to -which similar movements are referred, being altogether absent; but -probably, as De Bary believes, the cause may be found in the influence -of exosmose. - -The largest spermatia yet examined (those of _Peridermium Pini_) have a -length equal to 1/2500 of an inch, but their width seldom exceeds -1/100000 of an inch, whilst in others their length does not exceed the -width of those just named. - -Messrs. Tulasne affirm that all these corpuscles, as well as the -mucilaginous fluid, evolve an appreciable odour, resembling that of the -pollen of the willow. M. Léveillé compares the odour to that of orange -flowers, and M. de Bary to that of the evening primrose. - - - SPERMOGONES - -[Illustration: - - FIG. 1.—_Æcidium grossulariæ_. _c._ Cluster-cups. _s._ Spermogones. -] - -[Illustration: - - FIG. 2.—Section of ripe spermogones of _Æcidium Euphorbiæ_. _s._ - Spermatia. _a._ Sterigmatæ bearing spermatia (_De Bary_). -] - - -The spermogones do not always appear like pustules on the surface of the -leaves, for sometimes their presence is only indicated by minute -depressed punctures which are scarcely visible; generally, however, they -may be recognized by an obtuse, or otherwise a pointed, protuberance -that surmounts them. The margin of the orifice is sometimes furnished -with short hairs, but is more frequently ornamented with a pencil of -long hairs, which are stiff and erect, and of the colour of the enclosed -spermatia. - -In many of the species of _Æcidium_ the cups are disposed in a more or -less regular circle, the centre of which is occupied by a group of -spermogones; at the same time, the corresponding spot on the opposite -surface of the leaf will frequently be found also occupied by other -spermogones—in some instances in greater number than on the same surface -of the leaf on which the cups are seated. This is the case in the -_Æcidium_ which is found upon the leaves of the coltsfoot, and that of -the honeysuckle. - -Very bright orange-coloured spots may be observed in autumn (we have -encountered them often in August and September) upon the leaves of pear -trees, and which are covered with little tubercles, at first of the same -colour, but ultimately becoming brown. These pustules are so many -spermogones belonging to _Rœstelia cancellata_, a kind of cluster-cup -found in the same localities. These spots have long since been noticed, -and regarded as connected with the _Rœstelia_, but in what manner has -until recently been unknown. The Rev. M. J. Berkeley noticed them in the -English Flora in 1836, or at least the granulations on the upper -surfaces of the leaves bearing _R. cancellata_, _R. cornuta_, and _R. -lacerata_, and called them abortive pseudoperidia. Before this (in 1804) -they had been observed by Rebentisch. An examination of one of these -spots under a low power of the microscope, and afterwards a section of -one or more of the pustules, cut with a sharp razor, and viewed with a -higher power, will give an idea of the nature of the bodies we are -attempting to describe. During the past summer we have noticed very -similar orange spots on leaves of the berberry containing spermogones on -both surfaces, and these appeared before any cups had been found on that -plant. In this instance no cups were produced from the spots on the -leaves examined, and which were carefully noticed at intervals until -they withered and fell. - -In some instances, as in _Rœstelia cornuta_, which is found on the -leaves of the mountain-ash, the cups are produced on the lower, but the -spermogones almost exclusively on the upper surface. - -The spermogones of _Peridermium Pini_ are white, few in number, and are -developed, not only in the spring, but sometimes reappear in the autumn -upon the same leaves that produced them at the commencement of the year. - -In such instances as those of the _Æcidium_ of the spurge, and also the -goatsbeard, in which the cluster-cups are arranged in no appreciable -order, the spermogones are scattered amongst them, and even in some -instances appear on different leaves. The spermogones are common on the -wood spurge in spring, scattered over both surfaces of the leaves before -the cluster-cups make their appearance, and gradually these latter are -developed amongst them, commencing from the apex of the leaves and -proceeding in the order of their development towards the base. In this -instance the spermogones are bright yellow, as are afterwards the cups -and spores of the _Æcidium_. In most instances the appearance of the -spermogones precedes that of the sporiferous organs, but the latter -follow sufficiently speedy for perfect development before the decadence -of the spermogones takes place. - -After the expulsion of the spermatia and the fluid which accompanies -them, the whole mass dries up; and where many spermogones have been -clustered together in the same spot a brown homogeneous crust is formed -upon the epidermis; where they are produced singly, a brownish -incrustation is visible about the mouth of each spermogone. - -Re-agents applied to the spermogones whilst in full vitality indicate -the presence of a considerable amount of a protein substance, which, -with sugar and sulphuric acid, produces a deep purple red colour. - -From what we have already stated of the method of occurrence of these -organs, the following is the only order, apparently, preserved in their -development, although no definite rules can at present be affirmed. The -spore spots of cluster-cups are generally found upon the under surfaces -of the leaves on which they are produced, and the spermogones are most -numerous on the upper. When both the cluster-cups and the spermogones -appear in the same group on the same surface, the spermogones commonly -occupy the centre, and the cups are arranged in a circular manner about -them. In other, and fewer instances, both organs stand together -indiscriminately upon the same surface. - -The spermogones are also developed centrifugally, at least so far as at -present observed, for when they are produced in a cluster the central -one first opens and discharges its contents, and thus the development -proceeds outwards from the centre to the circumference. When the -spermogones are scattered, as in those of _Euphorbia_, they are first -observed at the apex of the leaf, whence they are developed in -succession towards the base. The latter should be sought for on the -young plants of the wood spurge in March or April, at which time we have -found them abundant at Darenth wood, near Dartford. - -It must not be concluded, from the fact that we have not yet adverted to -spermogones in connection with other fungi, that they are peculiar to -the _Æcidiacei_. Such is by no means the case. As we have hereafter -described other genera and species in which spermogones occur, it would -be out of place to enter upon further details here. Let it suffice -therefore that we state that they have been found in members of the -genera, _Aregma_, _Triphragmium_, _Puccinia_, _Lecythea_, _Trichobasis_, -and _Uredo_, but they have been found much more generally in _Rœstelia_ -and _Æcidium_ than in any other genus. - -As comparatively little is yet known of these bodies, a fair field is -open to the enterprising microscopist, with time at his disposal, and a -good store of perseverance, to win for himself renown in the discovery -of fresh facts, and the elucidation of some of the mysteries which yet -enshroud these interesting organisms. From the foregoing pages he will -learn the direction in which his researches should tend, and he may be -assured that every new fact is of importance when carefully ascertained. - - -[Illustration: - - Plate II. - W. West imp. -] - - ------------------------------------------------------------------------- - - - - - CHAPTER III. - - _DI-MORPHISM._ - - -BEFORE entering further and more fully upon the subject of this volume, -it may be advisable to attempt an explanation of a phenomenon of no -uncommon occurrence in many groups of Fungi, and which is termed -_di-morphism_. - -In the Uredines, or uredo-like fungi, as well as other of the -_Coniomycetes_ (in which the spores are the principal feature), the same -fungus appears under two or more distinct forms, not necessarily mere -differences of age, but so distinct that they have been regarded (and -some are so still) as different species belonging to different genera, -often far removed from each other, and bearing different names. One -plant, for instance, sprinkled over the under surface of a rose-leaf, -like turmeric powder, has its mycelium, or root-like threads, -penetrating the tissue, whilst bearing above its spherical -golden-coloured spores. Its vegetative system is complete, and, -apparently, its reproductive also; hence it seems to claim recognition -as a perfect plant, and under the name of _Uredo Rosæ_ was so -recognized, until microscopical investigation determined otherwise. Thus -it has been discovered that certain dark brown spots which appear later -in the season are produced upon the same mycelium, and are indeed -aggregations of more perfect and complex fruits of the same plant. -Before this point was satisfactorily decided, the brown spores, which -are borne on long stalks, and are themselves septate or divided -(apparently or really) by transverse partitions into a complex fruit, -received the name of _Puccinia Rosæ_. At this period, _Uredo Rosæ_ and -_Puccinia Rosæ_, or the yellow fungus and the dark brown fungus, were -believed to be distinct and different plants; now, on the contrary, they -are believed to be different forms of fruit produced by the same plant; -_i.e._, an instance of di-morphism. _Aregma mucronatum_, Fr., is the -present scientific name of what is regarded as the perfect fungus, -whilst the uredo-form either bears the name of _Lecythea Rosæ_, Lev., or -by some mycologists is rejected altogether as a spurious species. - -During the summer it is not uncommon to find the leaves of some grasses, -of the hop, of roses, and many other plants, covered with a kind of -white mould, which appears under the microscope as a multitude of small -transparent colourless cellules, generally attached to each other in a -moniliform or beaded manner. These moulds were long known under the -generic name of _Oidium_, to which genus the vine disease was also -referred. More minute investigation and more careful examination proved -that these moulds were not in themselves perfect plants, but merely -conditions of other fungi of a higher order, little differing it is true -in external appearance to the naked eye, but offering material -differences in structure under the microscope. Upon the white mould-like -threads, spherical bodies are produced in the autumn, containing little -sacs or asci filled with spores; and in this condition the plants are -arranged under the genus _Erysiphe_, whilst the species of _Oidium_ -which represented their imperfect condition, are excluded from the -system. Here, again, we have examples of _di-morphism_. - -In the Journal of the Microscopical Society, Mr. F. Currey has detailed -several instances of di-morphism which have fallen within his -experience. In one instance he has shown that a small simple spored -fungus, termed _Cryptosporium Neesii_, Ca., is only a state or condition -of a fungus with compound fruit, belonging to the _Sphœria_ section of -ascigerous fungi, called _Valsa suffusa_, Fr. Both plants are exactly -alike externally, but the perithecium, or flask-like receptacle -containing the fructification, in one instance only holds naked spores, -and in the other the spores are contained in little elongated vesicular -bags or asci, which are packed within the perithecium. - -Whilst writing this, one of the most wonderful books in a book-producing -age lies beside us; it is the second volume of a work on fungi, by the -brothers Tulasne; and this, as well as its predecessor, is devoted to -this very subject of a multiplicity of form in the fructification of -these plants. Illustrated by the most exquisite of engravings which art -has ever produced, it also unfolds many a page in the history of these -organisms, for which mycologists were not altogether unprepared. In -noticing this work, one of our most eminent authors on mycological -subjects quotes as an example _Dothidia ribis_, Fr., one of our most -common fungi, which occurs in the form of little black shields on dead -twigs of currants and goose-berries. Here we have, he says, naked spores -(_conidia_) growing on the external cells of the stroma; we have naked -spores of a second kind (_stylospores_) produced in distinct cysts -(_pycnides_); we have minute bodies of a third kind (_spermatia_) -produced again in distinct cysts, resembling very closely similar bodies -in lichens; and we have a third kind of cysts, containing the usual -sporidia in sausage-shaped hyaline sacs (_asci_). Even here, however, we -have not done with marvels; for if the stylospores are placed in water, -they produce in the course of twenty-four hours conidia of a second -order, exactly analogous to those which arise on the germination of the -spores of the rusts and mildews which affect our cereals and other -plants. - -Further reference is also made to three species of moulds, which M. -Tulasne has shown to be only varied forms of the mycelium of a species -of _Sphœria_ common to various plants; these moulds having been hitherto -regarded as fungi perfect in themselves. - -In the Uredines, to which much of this volume is devoted, the genera -known as _Lecythea_ and _Trichobasis_ are by some mycologists excluded -altogether, as containing only species which are mere forms of more -highly-developed uredines, such as _Puccinia_, _Aregma_, and others. On -the other hand, they are retained by those who possess a lingering doubt -whether both forms may not be distinct, though developed from the same -pustule. As the two forms are distinct in appearance, it will better -answer our present purpose to treat them separately, notwithstanding the -belief that, in a scientific point of view, the evidence is all in -favour of their union. - -In fungi of this kind the mycelium, or delicate root-like threads, -consists of thin filaments, which are spread through all parts of the -plant occupied by the parasite, traversing the intercellular passages, -but rarely perforating and entering the cells. This compacted and -interwoven mycelium forms a kind of cushion beneath each pustule, on -which the fruits of the parasite rest. By the increase of this cushion -and the swelling of the fruit, the epidermis which covers them is -distended, and ultimately ruptured, so that, when ripened, the spores -escape. It must be remembered that the fruit is of from two to four -kinds. Small bodies, called _spermatia_, which are derived from the -spermogones, and which have not yet been known to germinate; -_Stylospores_, produced either singly, or in bead-like, or moniliform, -strings, and which either precede or are associated with the true -spores; _Spores_, sometimes simple, but often complex; and _Sporidia_, -or secondary sporules, which are produced on the germinating threads of -the true spores. - -The various genera of these endophytes owe their distinctions to the -form, or mode of development of their true spores. In one instance these -spores are united in pairs, or divided by a septum, so that they are -two-celled: these are named _Puccinia_. In another instance the spores -are one-celled, and at first borne upon a stalk or peduncle, from which -they are detached in ripening: such are called _Trichobasis_. It is -unnecessary here to indicate all the variations to illustrate the fact -that the generic distinctions are based upon the characters of the true -spores. How unsatisfactory such a mode will appear, when subjected to -experience day by day, a botanist would suspect. In the same pustule, -resting upon the same cushion of mycelium, the spores of an _Aregma_ -will be found with those of a _Lecythea_, and those of a _Puccinia_ with -_Trichobasis_. More than this has even been affirmed. The alternation of -generations, known to students in the animal world, is here repeated in -the vegetable. Dr. de Bary declares that certain data appear to indicate -that _Æcidium_ constitutes not a genus by itself, but are organs in the -development of some other germs and species, possessing its spermogonia, -its _Æcidium_; its _Uredo_, and its spores, properly speaking; whilst in -others the _Uredo_-form the _Puccinia_-form, and the _Æcidium_-form may -alternate. It is not our intention to enter deeply upon the discussion -of this subject, of so little interest to the beginner, and so out of -place in an introduction to the study. That forms and conditions are -multifarious, and that an entire revision of the classification is -inevitable, are facts which do not require many words to establish. -Already it is to be feared that in this brief chapter we have said too -much, and must recommend its perusal again, when the names and -characters of the genera alluded to have been rendered more familiar. - -It could scarcely have been permitted that the student should go far -without being cautioned that there is such a thing as di-morphism in -microscopic fungi; and the explanation of such a phenomenon must -presuppose a certain amount of knowledge which, thus far, the reader -could not have acquired. Hence an anomaly, to escape from which an -ultimate return to the subject will be necessary. - -In a recent account of Dr. de Bary’s experiments,[3] an interesting -history is given of the development of a rust-like fungus, which is -common on many plants of the pea and bean tribe. As it may serve to -illustrate some of the preceding, as well as subsequent, remarks on -development, an abstract shall close this chapter. - -Footnote 3: - - De Bary—“Annales des Sciences Naturelles,” ser. 4, vol. xx. - -The spores of this species (_Uromyces appendiculatus_) are oboval cells, -terminated by a rounded point, provided with a deep brown, smooth, -_epispore_, or outer coating, and a distinct, but colourless -_endospore_, or inner coating. These enclose a granular matter, which -surrounds what has been termed the nucleus, but which appears to be a -vacuole. At the top of the epispore is a pore which is characteristic of -the genus. The spores are supported on a colourless, or slightly-tinted -pedicel of considerable length (Plate VII. fig. 150). By means of this -pedicel, the spores are attached to the fostering plant, on which they -form pustules or sori of a blackish colour, and variable extent. These -spores are ripened towards the end of summer or beginning of autumn. -During winter they remain in a state of repose, but in the following -spring the faculty of germination developes itself. At this period, when -moistened or placed on a humid soil, they germinate at the end of a few -days. The spore then emits a curved and obtuse tube, which soon ceasing -to elongate itself, gives origin to three or four sporidia, of a -reniform or kidney shape. When cultivated on moistened glass, these -sporidia also emit a short, thin, slender tube, which produce in turn -secondary sporidia. Here vegetation ends in the artificial culture above -indicated. - -When the sporidia are sown upon the epidermis of a favourable plant, the -germ-tube being emitted, penetrates the wall of any approximate cellule, -swells and increases into a cylindrical tube equal in thickness to the -original sporidia, and therefore four or five times the diameter of the -germ-tube before it entered the cellule. The contents of the sporidia -and external portion of its germ-tube pass into the portion within the -cellule, and then these external portions perish, and all evidence of -the entry is obliterated, except a very minute point at which the tube -remains attached to the inner surface of the wall of the cellule. The -enclosed tube soon elongates, divides, and becomes branched. These -branches perforate the inner walls of the epidermis, and pass into the -intercellular spaces of the parenchyma to become mycelium. This takes -place within 24 hours. A few days afterwards the mycelium is spread -through the parenchyma. At length the surface of the same spots which -had been sown in the first instance with the sporidia, become of a -whitish tint, rapidly increasing and intensifying. Three days after, -little protuberances appear on the surface of the white spots. These are -of an orange colour, and many of them are surmounted by a little drop of -mucilaginous fluid. These are _spermogones_. Their number daily -increases, and a little time after appear numerous large globular -protuberances intermingled with them. These soon rupture the epidermis, -and take the orange colour and cylindrical form of cluster-cups -(_Æcidium_). At length the summit of the peridia opens to allow the -escape of the _stylospores_. It is easy to assure oneself that the -spermogones and cluster-cups proceed from the mycelium of the sporidia -which had been sown. During several days the length and number of the -peridia of the _Æcidium_ continue to increase. One month after sowing, -brownish or blackish points make their appearance upon the whitish -spots, around, or intermingled with the cluster-cups. These increase -rapidly in number and magnitude. Examined by the microscope, they -present the ordinary fructification of _Uromyces_, mingled with -stylospores. Thus the mycelium of the cluster-cups engenders at the end -of its vegetation fruits equal in all points to those from whence they -are in the first instance derived. - -The stylospores of the cluster-cups possess the irregular, globular form -and structure of their congeners. They are filled with orange granular -matter, and provided with a colourless, finely-punctated epispore. When -these stylospores are sown on the moistened epidermis of a favourable -plant, the germ-tube at first creeps along the surface, but as soon as -its extremities find a stomate, it enters it and elongates itself in the -air-cavity below the orifice, receives the contents of the original -stylospore and exposed portion of its tube, then separates itself from -those parts, which become dispersed. The active part increases and -ramifies, and produces a mycelium which spreads through the -intercellular passages of the parenchyma. At the end of from six to -eight days, the whitish spots appear on the surface of the fostering -plant, and indicate that the fructification of the parasite is about to -commence. The epidermis is elevated and broken, and little brown -pustules appear through the openings. These are the _stylospores_ of -_Uredo_, which are produced in immense quantities, and soon cover the -pustules with a deep brown dust. Later, the formation of the stylospores -is arrested, and the true germinating spores appear in the same -pustules. - -The stylospores of _Uredo_ are borne singly at the top of short -filaments. On arriving at maturity they detach themselves. They are of a -globular form, with a reddish-brown epispore, provided with little -pointed prominences, and three pores at equal distances. After maturity -they germinate in precisely the same manner as the stylospores of the -cluster-cups. They enter only through the stomata of the epidermis. The -pulvinules are identical with those which the stylospores of _Æcidium_ -originate, and they also produce true spores at the end of their -vegetation. No other fruit arises from them. These organs, therefore, -always reproduce the same form to which they owe their origin. The -result of these investigations shows that the bean rust (_Uromyces -appendiculatus_), besides spermogones, possesses four sorts of -reproductive organs, which all serve to propagate the species, but that -one alone of them produces it in a form always identical, whilst the -others present well-marked alternations of generation. Hence it is -concluded that there are, - -I. _Spores_ which produce in germinating the promycelium, and - -II. _Sporidia._—These give place to a mycelium, which bears afterwards— - -III. _Æcidium._—Particular organs which engender stylospores, and which -produce— - -IV. _Uredo_, the second form of the stylospores, and later spores (No. -I.), which are always associated with _Uredo_ in the same pustule. The -spores and stylospores of _Uredo_ come also upon the old mycelium, which -has previously produced _Æcidium_. The _Uredo_ stylospores always -produce _Uredo_, and true spores. - - ------------------------------------------------------------------------- - - - - - CHAPTER IV. - - _MILDEW AND BRAND._ - - -DR. WITHERING’S “Arrangement of British Plants” in 1818 reached its -sixth edition. This is less than half a century ago, and yet the whole -number of species of Fungi described in that edition was only 564, of -which three hundred were included under the old genus _Agaricus_. Less -than eighty of the more minute species of Fungi, but few of which -deserve the name of microscopic, were supposed to contain all then known -of these wonderful organisms. Since that period, microscopes have become -very different instruments, and one result has been the increase of -Withering’s 564 species of British Fungi to the 2,479 enumerated in the -“Index Fungorum Britannicorum.” By far the greater number of species -thus added depend for their specific, and often generic characters, upon -microscopical examination. The proportion which the cryptogamic section -bears to the phanerogamic in our local Floras before 1818, now almost -involuntarily causes a smile. Even such authors as were supposed to pay -the greatest possible respect to the lower orders of plants could never -present an equal number of pages devoted to them, as to the higher -orders. Relhan, for instance, only occupies one-fifth of his “Flora -Cantabrigiensis,” and Hudson one-fourth of his “Flora Anglica,” with the -Cryptogamia. At the present time, it will be seen that, with a liberal -allowance for “hair-splitting,” the number of British species of -flowering plants scarcely exceeds three-fourths of the number of Fungi -alone, not to mention ferns, mosses, algæ and lichens, and yet we have -no “Flora” which contains them, and but a minority of our botanists know -anything about them. If we need excuse for directing attention to some -of the most interesting of these plants, let the above remarks suffice -in lieu of formal apology. - -“Mildew” is just one of those loose terms which represent no definite -idea, or a very different one to different individuals. Talk of _mildew_ -to a farmer, and instantly he scampers mentally over his fields of -standing corn in search of the brown lines or irregular spots which -indicate the unwelcome presence of _Puccinia graminis_, known to him, -and to generations of farmers before him, as “mildew.” Try to convince a -Norfolk farmer that anything else is “mildew,” and he will consider you -insane for your pains. Speak of _mildew_ in your own domestic circle, -and inquire of wives, or daughters, or servants, what it means, and -without hesitation another, and even more minute species of fungus, -which attacks damp linen, will be indicated as the true mildew, to the -exclusion of all others; and with equal claims to antiquity. Go to -Farnham, or any other hop-growing district, and repeat there your -question,—What is _mildew_?—and there is every probability that you will -be told that it is a kind of mould which attacks the hop plant, but -which differs as much from both the mildew of the farmer and the -laundry-maid as they differ from each other. The vine-grower has his -mildew, the gardener his mildewed onions, the stationer his mildewed -paper from damp cellars, the plasterer his mildewed walls, and in almost -every calling, or sphere in life, wherever a minute fungus commits its -ravages upon stock, crop, or chattels, to that individual owner it -becomes a bug-bear under the name of “mildew.” Reluctantly this vague -term has been employed as a portion of the title to this chapter, but it -must be limited in its application to the “mildew of corn,” known to -botanists as _Puccinia graminis_, and _not_ to include the numerous -other microscopic Fungi to which the name of _mildew_ is often applied. - -The origin of this term and its true application may undoubtedly be -traced to _mehl-thau_, “meal dew.” A singular proof of the ignorance -which prevails in regard to all the fungal diseases of corn, may be -found in the fact that at least one of our best etymological -dictionaries states that the _mildew_ in corn is the same as the _ergot_ -of the French. Had the writer ever been a farmer, he would have known -the difference; had he ever seen the two, he could scarcely have made -such a mistake. It is barely possible for him ever to have heard the -ergot of grain called by the name of _mildew_. - -How long this disease has been known, is an unsolved problem. About the -middle of the last century a tract was published on this subject in -Italy, but this was probably not even the first intimation of its -fungoid character. Before such conclusion had been arrived at, men may -have struggled in the dark, through many generations, to account for a -phenomenon with which they were doubtless familiar in its effects. In -1805, Sir Joseph Banks published his “Short Account,” illustrated by -engravings from the inimitable drawings of Bauer, whereby many in this -country learnt, for the first time, the true nature of _mildew_. - - -[Illustration: - - Plate III. - W. West imp. -] - - -With a view to the clearer understanding of these parasites in the -phases of their development, let us select one, and we cannot do better -than adhere to that of the wheat and other graminaceous plants. A fine -day in May or June dawns upon our preparations for a stroll, far enough -into the country to find a wheat-field. Even now, with the area of the -metropolis constantly widening, and banishing farmers and wheat fields -farther and farther from the sound of Bow-bells, a corn field may be -reached by a good stiff walk from Charing-Cross, or a six-penny ride at -the most, in nearly any direction. Having reached the field, it may be -premised that a walk into it of less than twenty yards will be sure to -reward you with the fungus we are in quest of. Look down at the green -leaves, especially the lower ones, and you will soon find one apparently -grown rusty. The surface seems to be sprinkled with powdered red ochre, -and grown sickly under the operation. Pluck it carefully, and examine it -with a pocket lens. Already the structure of a healthy leaf is familiar -to you, but in the present instance the cuticle is traversed with -numerous longitudinal cracks or fissures, within which, and about their -margins, you discern an orange powder, to which the rusty appearance of -the leaf is due. Further examination reveals also portions in which the -cuticle is distended into yellowish elongated pustules, not yet -ruptured, and which is an earlier stage of the same disease. This is the -“rust” of the agriculturist, the _Trichobasis rubigo-vera_ of botanists, -the first phase of the corn mildew. - -To know more of this parasite, we must have recourse to the microscope; -having therefore collected a few leaves for this purpose, we return -homewards to follow up the investigation. We will not stay to detail the -processes of manipulation, since these will not offer any deviation from -the ordinary modes of preparation and examination of delicate vegetable -tissues. - -The vegetative system of the “rust,” and similar fungi, consists of a -number of delicate, simple, or branched threads, often intertwining and -anastomosing, or uniting one to the other by means of lateral -branchlets. These threads, termed the mycelium, penetrate the -intercellular spaces, and insinuate themselves in a complete network, -amongst the cells of which the leaf, or other diseased portion of the -plant, is composed. High powers of the microscope, and equally high -powers of patience and perseverance, are necessary to make out this part -of the structure. We may regard the whole mycelium of one pustule, or -spore-spot, as the vegetative system of one fungal plant. At first this -mycelium might have originated in a number of individuals, which -afterwards became confluent and combined into one for the production of -fruit, that is to say, an indefinite number of points in the vicinity of -the future mycelium developed threads; and these, in the process of -growth, interlaced each other, and ultimately, by means of transverse -processes, became united into one vegetative system, in which the -individuality of each of the elementary threads became absorbed, and by -one combined effort a spore-spot, or cluster of fruit, was produced. In -the first instance a number of minute, transparent, colourless cellules -are developed from the mycelium: these enlarge, become filled with an -orange-coloured endochrome, and appear beneath the cuticle of the leaf -as yellowish spots. As a consequence of this increase in bulk, the -cuticle becomes distended in the form of a pustule over the yellow -cellules, and at length, unable longer to withstand the pressure from -beneath, ruptures in irregular, more or less elongated fissures (Plate -VII. fig. 141), and the yellow bodies, now termed _spores_ (whether -correctly so, we do not at present inquire), break from their short -pedicels and escape, to the naked eye presenting the appearance of an -orange or rust-coloured powder. In this stage the spores are globose, or -nearly so, and consist of but one cell Plate VII. figs. 142, 144). It -will afford much instructive amusement to examine one of these ruptured -pustules as an opaque object under a low power, and afterwards the -spores may be viewed with a higher power as a transparent object. The -difference in depth of tint, the nearly colourless and smaller immature -spores, and the tendency in some of the fully matured ones to elongate, -are all facts worthy of notice, as will be seen hereafter. - -A month or two later in the season, and we will make another trip to the -cornfield. Rusty leaves, and leaf-sheaths, have become even more common -than before. A little careful examination, and, here and there, we shall -find a leaf or two with decidedly brown pustules intermixed with the -rusty ones, or, as we have observed several times during the past -autumn, the pustules towards the base of the leaf orange, and those -towards the apex reddish-brown. If we remove from the browner spots a -little of the powder, by means of a sharp-pointed knife, and place it in -a drop of water or alcohol on a glass slide, and after covering with a -square of thin glass, submit it to examination under a quarter-inch -objective, a different series of forms will be observed. There will -still be a proportion of subglobose, one-celled, yellow spores; but the -majority will be elongated, most with pedicels or stalks, if they have -been carefully removed from the leaf, and either decidedly two-celled, -or with an evident tendency to become so. The two cells are separated by -a partition or dissepiment, which divides the original cell transversely -into an upper and lower cell, with an external constriction in the plane -of the dissepiment (Plate IV. fig. 59). These bilocular or two-celled -spores are those of the “corn mildew” (_Puccinia graminis_), which may -be produced in the same pustules, and from the same mycelium, as the -“corn rust,” but which some mycologists consider to be a distinct -fungus, others only a modification or stage of the same fungus. After an -examination of the different forms in the allied genera to which these -chapters are devoted, we shall be able with less of explanation and -circumlocution to canvass these two conflicting opinions. - -Let us proceed, for the third and last time, to our cornfield, when the -corn is nearly or fully ripe, or let us look over any bundle of straw, -and we shall find blackish spots, from the size of a pin’s head to an -inch in length, mostly on the sheaths of the leaves, often on the culm -itself. This is the fully developed _mildew_, and when once seen is not -likely afterwards to be confounded with any other parasite on straw -(fig. 57). The drawings of Bauer have already been alluded to. Bauer was -botanical draughtsman to George III., and his exquisite drawings, both -of the germination of wheat and the fungi which infest it, are marvels -of artistic skill. A reduced figure from part of one of his drawings is -given (Plate IV. fig. 58), exhibiting a tuft of the bilocular spores of -_Puccinia graminis_ bursting through a piece of wheat straw. These -closely-packed tufts or masses of spores, when examined with a common -lens, seem, at first, to resemble the minute sorus of some species of -fern; but when seen with higher powers, the apparent resemblance gives -place to something very different. The tufts consist of multitudes of -stalked bodies, termed spores, which are constricted in the middle and -narrowed towards either extremity. The partition, or septum, thrown -across the spore at the constriction, separates it into two portions, -each of which consists of a cell-wall enclosing an inner vesicle filled -with the endochrome (fig. 59) or granular contents, in which a nucleus -may often be made out. This species of _Puccinia_ is very common on all -the cereals cultivated in this country, and on many of the grasses. A -variety found on the reed was at one time considered a distinct species; -but the difference does not seem sufficient to warrant a separation. -However near some other of the recognized species may seem to -approximate in the form of the spores, a very embryo botanist will not -fail to observe the distinctive features in the spores of the corn -mildew, and speedily recognize them amongst a host of others; subject, -as they may be, to slight deviations in form, resulting either from -external pressure, checks in development, or other accidental -circumstances, or the variations of age. - -There is no doubt in the minds of agriculturists, botanists, _savans_, -or farm-labourers, that the mildew is very injurious to the corn crop. -Different opinions may exist as to how the plants become inoculated, or -how infection may be prevented or cured. Some have professed to believe -that the spores, such as we have seen produced in clusters on wheat -straw, enter by the stomata, or pores, of the growing plant, “and at the -bottom of the hollows to which they lead they germinate and push their -minute roots into the cellular texture.” Such an explanation, however -plausible at first sight, fails on examination, from the fact that the -spores are too large to find ingress by such minute openings. It is -improbable that the _spores_ enter the growing plant at all. The -granular contents of the spores may effect an entrance either through -the roots or by the stomata, or the globose bodies produced upon the -germination of the spores may be the primary cause of infection. We are -not aware that this question has been satisfactorily determined. It is -worthy of remembrance by all persons interested in the growth of corn, -that the mildew is most common upon plants growing on the site of an old -dunghill, or on very rich soil. As the same _Puccinia_ is also to be -found on numerous grasses, no prudent farmer will permit these to -luxuriate around the borders of his fields, lest they should serve to -introduce or increase the pest he so much dreads. - -The germination of the spores of the corn mildew is a very interesting -and instructive process, which may be observed with a very little -trouble. If the spores be scraped from the sori of the preceding year -(we are not sure that those of the current year will succeed), and kept -for a short time in a damp atmosphere under a glass receiver, minute -colourless threads will be seen to issue both from the upper and lower -divisions of the spores. These will attain a length several times that -of the spores from whence they spring. The extremities of these threads -ultimately thicken, and two or three septæ are formed across each, -dividing it into cells, in which a little orange-coloured endochrome -accumulates. From the walls of each of these cells, or joints, a small -pedicel, or spicule, is produced outwards, the tip of which gradually -swells until a spherical head is formed, into which the orange-coloured -fluid passes from the extremities of the threads.[4] A quantity of such -threads, bearing at their summits from one to four of these -orange-coloured, spherical, secondary fruits, supply a beautiful as well -as interesting object for the microscope. When matured, these globose -bodies, which Tulasne has called _sporidia_, fall from the threads, and -commence germinating on their own account. It is not impossible that the -sporidia, in this and allied genera, may themselves produce a third and -still more minute fruit, capable of diffusion through the tissues of -growing plants, or gaining admission by their stomata. Nothing of the -kind, however, has yet been of certainty discovered. - -Footnote 4: - - Similar in all essential particulars to the germination of _Aregma_ - (Plate III. fig. 45). - -Forty other species of _Puccinia_ have been recorded as occurring in -Great Britain, to all of which many of the foregoing remarks will also -apply—viz., such as relate to their two-celled spores being found -associated with, and springing from, the same mycelium as certain -orange-coloured one-celled spores; and also the main features of the -germinating process. - - -[Illustration: - - Plate IV. - W. West imp. -] - - -A very singular and interesting species is not uncommon on the more -delicate grasses, being found chiefly confined to the leaves, and -produced in smaller and more rounded, or but slightly elongated, patches -(Plate IV. fig. 60). We have met with it plentifully amongst the turf -laid down in the grounds of the Crystal Palace at Sydenham, and also on -hedge-banks and in pastures. The spores are rather smaller than those of -_Puccinia graminis_, but, like them, much elongated, slightly -constricted, and borne on persistent peduncles. The most prominent -distinction may be found in the apices of the spores, which, in this -instance, are not attenuated, but crowned with a series of little -spicules, or teeth, whence the specific name of _coronata_ has been -derived (Plate IV. fig. 62). - -The Labiate family of plants and its ally the Scrophulariaceæ are also -subject to the attacks of several kinds of Brand, a name, by the bye, -often applied locally to the corn mildew and other similar parasites, -and which may have originated in the scorched or _burnt_ appearance -which the infected parts generally assume. In the former natural order -the different kinds of mint, the ground-ivy, the wood-sage, and the -betony, and in the latter, the water figwort and several species of -veronica, or speedwell, are peculiarly susceptible; and on most a -distinct species of _Puccinia_ is found. To provide against doubt which -the less botanical of our readers may possess of the meaning or value of -the term _Puccinia_, which has already occurred two or three times in -this chapter, a brief explanation may be necessary, which more -scientific readers will excuse. - -In botany, as in kindred sciences, acknowledged species have their -trivial, or specific name, generally derived from the Latin. In the last -species referred to, this was _coronata_, meaning _crowned_, in -reference to the coronated apex of the fruit. Any indefinite number of -species with some features in common are associated together in a group, -which is termed a _genus_, and the term prefixed to the specific name of -each species constituting that genus is its generic name, also commonly -derived from the Latin or Greek. In this instance it is _Puccinia_, -derived from the Greek _puka_, meaning _closely packed_, singularly -applicable to the manner in which the spores are packed together in the -pustules. The common features, or generic distinctions, of this genus, -are uniseptate spores borne on a distinct peduncle. - -In returning to the species found on Labiate plants, let us suppose -ourselves to have strolled towards Hampstead Heath, and south of the -road leading from Hampstead to Highgate, near certain conspicuous and -well-known arches, built for a purpose not yet attained, are two or -three muddy ponds nearly choked up with vegetation. Some fine autumnal -afternoon, we must imagine ourselves to have reached the margin of the -most northern of these ponds, and amidst a thick growth of reeds, -sedges, and other water-loving plants, to have found the water-mint in -profusion and luxuriance, with every leaf more or less occupied, on its -under surface, with the yellow spores of a species of rust -(_Trichobasis_) mixed with the browner septate spores of the mint brand -(_Puccinia Menthæ_). This is common also on the horse-mint and -corn-mint; we have found it on the wild basil and wild thyme, and once -only on marjoram. Having collected as many leaves as we desire, and -returned to home and the microscope, we proceed to examine them in the -same manner as we have already examined the mildew, and as a result of -such proceeding arrive at the following conclusions:—The pustules are -small and round, never elongated as in the corn mildew, and generally -confined to the under surface of the leaves (Plate IV. fig. 69). The -spores are subglobose, slightly constricted, and the two cells nearly -two hemispheres, with their flat surfaces turned towards each other -(fig. 70). The form delineated in figure 75 is that of the sorus of many -of the epiphytal brands, the centre being occupied by the closely-packed -spores, surrounded to a greater or less extent by the remains of the -ruptured epidermis. - -Although the species of Puccinia (_P. glechomatis_) found on the leaves -of the ground-ivy is said to be very common, we sought it in vain -amongst every cluster of that plant met with during last summer and -autumn, until, nearly despairing of finding it at all, we at last -encountered a plot of ground-ivy covering the ground to the width of two -or three yards, and in length eight or ten, nearly every plant being -attacked by the _brand_. This was in the corner of a pasture, and the -only time we found infected plants. The fungus, however, may be as -common as the plant in other localities. The pustules on the leaves are -larger than those of the mints, and also confined to the inferior -surface (fig. 73). The spores are elliptic and but slightly constricted; -the apex is often pointed, though not always so much as in our figure -(fig. 74). - -Of other species found on allied plants we have not considered it -necessary to give figures, or write much. The betony brand (_P. -Betonicæ_, DC.) does not seem to be common enough to be readily found by -any one desiring to examine it for himself; and the same may be said of -the figwort brand (_P. Scrophulariæ_, Lib.), the wood-sage brand (_P. -Scorodoniæ_, Lk.), and the speedwell brand (_P. Veronicarum_, DC.); all -of these are, however, characterized by a distinct feature, or features, -which have been considered of sufficient importance to constitute a -separate species. - -We have had occasion to refer incidentally to the brand found on the -under surface of the leaves of the wood-anemone (_P. Anemones_, P.). -This is one of the earliest and commonest species. Go wherever the -wood-anemone abounds, in any of the woods lying immediately to the north -of the metropolis, or any of the woods in Kent, and from March to May it -will not be difficult to find attenuated, sickly-looking leaves, with -the under surface covered with the pustules of this brand, looking so -like the sori of some fern (fig. 65) that it _has_ been, and still _is_, -sometimes considered as such. In Ray’s “Synopsis” (3rd edition, 1724), -it is described in company with the maidenhair and wall-rue ferns; a -figure is given of it in the same work (t. iii. fig. 1), and it is -stated,—“this capillary was gathered by the Conjuror of Chalgrave.” -When, afterwards, it was better understood, and the spots came to be -regarded as true parasitic fungi, it still for a long time continued to -bear the name, not even yet quite forgotten, of the Conjuror of -Chalgrave’s fern. - -An examination of the spores, both collectively in the pustules, and -separately under a high power, will not fail to convince any one who has -examined only the species we have already alluded to, that this parasite -on the anemone (_P. Anemones_) is a true _Puccinia_, and a most -interesting one. The two cells of the spores are nearly spherical, and -the constriction is deeper and more positive than in any of the -preceding. Moreover, the surface of the spore is minutely and -beautifully echinulate, or covered with erect spines (Plate IV. fig. -66). Some few other of the species found in Britain have echinulate -spores, but those are not common like the present. One word of caution -to the amateur in search of the _Puccinia_ on the anemone. It will be -fruitless looking for it on the large foliaceous bracts of the -flower-stalk, since these may be turned up carefully, till the back -aches with stooping, ere a solitary pustule will be found; but the true -leaves, proceeding from the rhizomes, are certain soon to afford you -specimens. - -Everybody knows the dandelion, but it is not every one who has noticed -the fungi found upon its leaves. These are most commonly of two kinds, -or probably the unilocular and bilocular forms of the same species: the -latter we have found in the month of May, and the former in August and -September. The lower leaves of young seedlings have generally rewarded -us with the best specimens of the septate-fruited brand (_Puccinia -variabilis_, Grev.). The pustules occur on both sides of the leaf, and -are very small and scattered (fig. 82). The spores are singularly -variable in form: sometimes both divisions are nearly equal in size; -sometimes the upper, and sometimes the lower, division is the smallest; -occasionally the septum will be absent altogether; and more rarely, the -spores will contain three cells. From the very variable character of the -spores (fig. 83), the specific name has been derived. - -No species in the entire genus makes so prominent an appearance as the -one found on the radical leaves of the spear thistle (_Carduus -lanceolatus_). This latter plant is exceedingly abundant, and so is its -parasite (_Puccinia syngenesiarum_, Lk.). From the month of July till -the frosts set in we may be almost certain of finding specimens in any -wood. The leaves have a paler roundish spot, from one-twelfth to -one-fourth of an inch in diameter, on the upper surface, and a -corresponding dark brown raised spot on the under surface, caused by an -aggregation of pustules, forming a large compound pustule, often partly -covered with the epidermis. The individual pustules are small, but this -aggregate mode of growth gives the clusters great prominence, and -therefore they are not easily overlooked (Plate IV. fig. 63). Although -not confined to this species of thistle, we have not yet found this -_Puccinia_ on any other plant. The spores are elliptical, rather -elongated, constricted, and without spines (fig. 64). - -Other species of _Puccinia_ are found on Composite plants, but with none -of these is the present fungus likely to be confounded, if regard be had -to its peculiar habit. The leaves, for instance, of the common knapweed -(_Centaurea nigra_) are often sprinkled with the small pustules of the -centaury brand (_Puccinia compositarum_, Sch.); these generally occupy -the under surface of the lower radical leaves (fig. 67); occasionally a -few of the pustules appear on the upper surface. We have not often found -this fungus in the neighbourhood of London on the leaves of the -knapweed, but, on the other hand, we have encountered it very commonly -on those of the saw-wort (_Serratula tinctoria_). The spores are oval, -scarcely constricted, and not attenuated in either direction (fig. 68). -Other Composite plants than those above named are liable to attacks from -this parasite. - -In our school-days we remember to have spent many a stray half-hour -digging for “earthnuts,” under which name we, as well as our elders and -betters, knew the tubers of _Bunium flexuosum_. Not then, nor for many -years after, did we notice, or regard if we did notice, the distorted -radical leaves and leaf-stalks, and the blackish-brown spots, which -reveal the cause in the presence of a brand, or parasitic fungus, of -this genus (_Puccinia Umbelliferarum_, DC.), which is extremely common -on this, as well as some other allied plants. If any spot is searched -where this plant grows in any profusion, before the flowering stalks -have made their appearance above the surrounding grass, this _Puccinia_ -will be readily found by the twisted, contorted, sickly appearance of -the infested leaves (fig. 71), the petioles of which are often swollen -and gouty in consequence. The sporidia are shortly stalked, and -generally very much constricted (fig. 72). The species found on the -stems of the hemlock, and also that on Alexanders (_Smyrnium -Olusatrum_), are distinct; the spores of the latter being covered with -tubercles or warts (figs. 55, 56). During a botanical ramble through -Darenth Wood in April of the year just passed away, in some parts of -which the sanicle abounds, we found the bright glossy leaves of this -singular and interesting plant freely sprinkled with the pustules of a -_Puccinia_ (_P. Saniculæ_, Grev.), which is not at all uncommon on this, -but has not hitherto been found on any other plant. Dr. Greville, of -Edinburgh, was the first to describe this, as well as many other of our -indigenous minute Fungi. For many years he has toiled earnestly and -vigorously at the lower cryptogams, as evidenced by his “Scottish -Cryptogamic Flora,” published in 1823; and yet his continual additions -to the records of science show him to be earnest and vigorous still. - -We have by no means exhausted the catalogue of Fungi belonging to this -genus found in Britain, nor even those commonly to be met with; but the -fear of prolixity, and the desire to introduce a description of other -forms into the space still remaining to us, prompt us to dismiss these -two-celled brands with but a brief allusion to such as we cannot -describe. Box-leaves are the habitat of one species, and those of the -periwinkle (Plate VI. fig. 132) of another. One vegetates freely on the -leaves of violets through the months of July and August, and another -less frequently on the enchanter’s nightshade. Several species of -willow-herb (_Epilobium_) are attacked by one _Puccinia_ (Plate IV. -figs. 78, 79), and a single species by another. Plum-tree leaves, -bean-leaves, primrose leaves, and the half-dead stems of asparagus, have -their separate and distinct species, and others less commonly attack the -woodruff, bedstraw (Plate VIII. figs. 172, 173), knotgrass, ragwort, and -other plants less common, more local, or, to the generality of the -non-botanical, but imperfectly known. - -We have found, not uncommonly in the autumn, the scattered pustules of a -brand on the stems and leaves of the goat’s-beard, occupying the places -which were scarred with the remains of cluster-cups that had flourished -on the same spots a month or two previously (Plate IV. fig. 76). The -pustules are by no means minute, but elongated and bullate; the spores -beautifully studded with warts (Plate IV. fig. 77). This species cannot -certainly be identical with _Puccinia compositarum_ (Schlecht), _P. -syngenesiarum_ (Lk.), or _P. tragopogonis_ (Corda). In none of these do -the spores appear to be warted, and the habits of both the latter are -different. Its nearest associate appears to be _P. centauriæ_ (Corda), -at least in the fruit, and whilst the form and character of these organs -are considered of any value in the determination of species, smooth -spores cannot be associated, we think, with tuberculate or echinulate -spores under the same name. - -In the spores of the species to which attention has been more specially -directed we have types of the principal forms. In the “corn-mildew” they -are elongated, and tapering towards either end; in the “coronated brand” -the apex is crowned with spicular processes; in the “wind-flower brand” -the entire spores are echinulate; in the “mint brand” they are globose; -in the “composite brand” elliptic; in the “earth-nut brand,” nearly cut -in two at the septum; and in the “dandelion brand,” so variable in form -that no two are precisely alike. On the other hand, all are -characterized by a transverse septum dividing each spore into two cells. - - ------------------------------------------------------------------------- - - - - - CHAPTER V. - - _COMPLEX BRANDS._ - - -FROM the twin-spored genus we pass to another, in which the spores are -usually divided into three cells, and which, from this cause, has been -named _Triphragmium_. Only one species has hitherto been found in this -country, and _that_ not very commonly, on the leaves of the -meadow-sweet, _Spiræa ulmaria_ (Plate III. fig. 47). Externally, it much -resembles, in the size and character of the pustules, many of the -above-named brands, but when seen under the microscope this similarity -disappears. In general outline the spores are nearly globose, and -externally papillose. In one species, found on the Continent, but not -hitherto in Great Britain, the spores are covered with curious -long-hooked spines, by means of which they adhere tenaciously to each -other. In germination, the spores of _Triphragmium_ do not offer any -noteworthy deviation from those of _Puccinia_,[5] and the chief interest -of our indigenous species lies in the three-celled form of its spores -(fig. 48), to which occasionally those of _Puccinia variabilis_ -approximate, and may be regarded as the link which unites the two -genera. - -Footnote 5: - - Mr. Currey has only seen the tips of the germinating threads swell, - and become septate, each of the joints thus formed falling off and - germinating without producing spherical sporidia; whilst Tulasne - figures globular sporidia, as will be seen in our fig. 49, reduced - from the figure by Tulasne.—(_Vide_ Currey, in “Quarterly Journal of - Microscopical Science,” 1857, pp. 117, &c.) - -The old story of “Eyes and no Eyes” is too often literally true, not -only with the children it was written to amuse and instruct, but also -with children of a larger growth who scorn such baby tales, and disdain -such baby morals. Out of more than a thousand indigenous species of -microscopic fungi, of which there is generally some evidence afforded of -their presence visible to the naked eye, how few are there of the -millions that inhabit our island who can count twenty species that they -have ever seen; still fewer that have noticed one hundred. Amongst the -twenty species known to the few will probably be included one which -appears in autumn in prominent black spots, the size of a large pin’s -head, or half a turnip seed, with the flat face downwards, sprinkling -the under surface of blackberry leaves (fig. 39); with larger, reddish, -purplish, or reddish-brown spots on the upper to indicate the presence -of the fungus beneath. Just at the time when blackberries are ripe, -these spots are in perfection on the leaves, and _their_ eyes must have -been sadly at fault who could ever have gathered their own blackberries -without seeing the discoloured leaves. The coloured spots on the face of -the leaf are due to the diseased state of the tissues caused by the -parasite on the opposite surface. As much of the leaf as contains two or -three of the black pustules should be removed carefully with a knife or -sharp scissors, and submitted to microscopical examination; each will be -seen to consist of a dense tuft of blackish, elongated, stalked bodies, -clustered as in fig. 44, but much more numerously and closely packed -together. These are the spores of the blackberry brand (_Aregma -bulbosum_, Fr.). A few of these spores should be removed on the point of -a sharp penknife, placed on a glass slide with a drop of distilled water -or alcohol, covered with thin glass, and then viewed with a quarter-inch -objective. Each spore has a stalk longer than itself, thickened below, -and containing a yellow granular core. The spore itself is much longer -than in any of the _Pucciniæ_, of a dark brown colour, and apparently -divided by several transverse partitions into three, four, or more -cells, the whole surface being covered with minute warts or prominences -(Plate III. fig. 41). - -In 1857, Mr. F. Currey investigated the structure of these spores, and -the results of these experiments were detailed in the “Quarterly Journal -of Microscopical Science.” One conclusion arrived at was, that “the idea -of the fruit consisting of sporidia united together and forming a chain, -is certainly not in accordance with the true structure. The sporidia are -not united to one another in any way, but, although closely packed for -want of space, they are in fact free in the interior of what may be -called a sporangium or ascus.” To arrive at this conclusion, careful -examination was necessary, and new modes of manipulation essential. The -details of one method employed were to the following effect:—A -sufficient number of spores were removed on the point of a lancet, and -placed on a slide in a drop of alcohol. Before the spirit was quite -evaporated, two or three drops of strong nitric acid were added, and the -whole covered with thin glass. The slide was then warmed over a -spirit-lamp, the acid not being allowed to boil, but only gradually -heated to boiling point. By this means the fruit was found to consist of -an outer membrane, nearly transparent, and studded with tubercles; that -this membrane enclosed a number of cells which constituted the apparent -joints, and which were naturally flattened at either end by mutual -pressure. When the outer membrane was dissolved or ruptured, these cells -escaped, and became detached from each other. The cells, thus set free, -exhibited a brownish or yellow ring around a paler area, in the interior -of which an inner cell was visible, sometimes globular, often irregular -in shape. The examination of the ring was not entirely satisfactory; it -appeared to be sometimes marked with concentric lines having the -appearance of wrinkles. The inner cell had granular contents and a -central nucleus. When perfectly free they were spherical in form, with a -distinct membrane of their own; and colourless, except when acted upon -by reagents. The means employed to determine the existence of these -cells was to soak the spores in muriatic acid; then, upon pressure of -the glass cover, the outer membrane and ringed cells were ruptured, and -the inner cell escaped (Plate III. fig. 46). - -Germination may be induced in these spores by keeping them in a moist -atmosphere (fig. 45); but the mode does not differ from that described -above as occurring in the “corn mildew.” Mr. Currey writes:—“I know no -microscopical object of greater beauty than a number of fruits of -_Phragmidium_ in active germination.” By _Phragmidium_ he means the -_Aregma_ of this work, of which _Phragmidium_ is a synonyme. - -Well may the reader remark on arriving thus far, “Does all this -examination and detail refer to the fruit borne in the little blackish -spots on bramble leaves, which I have hitherto overlooked?” Ay, and to -several similar spots on other plants. Examine carefully the raspberry -leaves in your garden, and you will probably find similar, but smaller, -pustules also on the under surface (Plate III. fig. 42). We say -_probably_, because none of our British species seem to be equally -uncommon with this. During the past year we examined hundreds of plants, -and did not find a single pustule. This species was named by Dr. -Greville _Aregma gracilis_, which name it still continues to bear (fig. -43). Such a fate will not await you if you should proceed in the autumn -to some chalky district where the burnet is common. Go, for instance, to -Greenhithe or Northfleet, on the North Kent Railway, in August or -September, where the burnet is plentiful, and the leaves will present -the appearance of having been peppered beneath, from the number of -minute pustules of the burnet brand scattered over the under surface -(fig. 30, upper leaflets). Or if you prefer collecting nearer home, -visit some neighbouring garden, if your own does not contain many roses, -and the leaves will be found equally prolific in an allied species (fig. -36). Should gardens and roses be alike unattainable, any bank or wood -will furnish the barren strawberry (_Potentilla fragariastrum_), and -during the latter part of the summer, or in autumn, another species of -_Aregma_ will not be uncommon on the under surface of the leaves (fig. -33). All these species will be found accompanied by the orange spores of -species of _Lecythea_, which some mycologists consider to be distinct -fungi, and others to be merely forms or conditions of _Aregma_. These -spores are represented in Plate III. figs. 31, 34, 37, and 40. From the -magnified figures of the spores of the different species of _Aregma_ -(figs. 32, 35, 38, 41, and 43), it will be apparent that they have all -certain features in common, _i.e._, cylindrical spores containing from -three to seven cells. This may be called the _generic_ character, common -to all the species of the genus _Aregma_. Again, each species will be -observed to possess its own distinct features, which may be termed its -_specific_ character. In one, the apex of the spores will be obtuse, in -another acutely pointed, in another bluntly pointed, &c. In one species -the number of cells will usually be four, in another five or six, in -another seven or eight. The stem in one species will be slender and -equal, in another thickened or bulbous. So that in all there will be -some permanent peculiarity for each not shared by the others. - -One other form of brand (_Xenodochus carbonarius_), presenting, it is -believed by some, generic differences from all that we have as yet -noticed, remains to be briefly alluded to. This form appears to be very -uncommon in this country, but, when found, is parasitic on the leaves of -the great burnet (_Sanguisorba officinalis_), a plant of local -distribution. The parasite appears to the naked eye in small tufts or -pustules resembling those of an _Aregma_, but, when microscopically -examined, the cells of the spores are found to be numerous, indeed, -considerably more than in the most complex _Aregma_ (fig. 29). This, -however, seems to be the only distinction, for the cells are free in the -interior of the investing membrane, and in all points of structure, in -so far as it has been examined, identical with _Aregma_. Whether it is -logical to consider a four-celled spore an _Aregma_, and a seven-celled -spore an _Aregma_, and exclude a ten or twelve-celled spore from the -same genus on account of the number of its cells, does not appear to us -clearly answerable in the affirmative. - -During the course of this and the preceding chapter we have passed -rapidly through four genera of parasitic fungi so nearly allied, that -one is almost led to doubt the validity of the generic distinctions. -These may be presented briefly thus:— - - Spores two-celled PUCCINIA. - - Spores three-celled TRIPHRAGMIUM. - - Spores four to AREGMA. - seven-celled - - Spores many-celled XENODOCHUS. - -It has been seen that the habit, mode of growth, germination, and -structure, except in the number of cells, scarcely differ; but it is not -our province here to enter upon the discussion of such a subject. - -The association of one-celled, orange-coloured spores with the brown two -or more celled spores passed in review is another feature worthy of a -passing notice, and which opens a field for discussion. It is generally -admitted that these two forms are the production of the self-same -mycelium or vegetative system, but it is not so generally admitted that -they are but two forms or phases of the fruit of the same plant. It is -not at all uncommon in the history of mycology to find two forms which -were for a long time considered to be distinct plants producing -different forms of fruit, and which bore different names, and were -located in different genera, at length proved to be only the self-same -plant in different conditions, and ending in one name being expunged -from the list. Such a fate probably awaits, at no distant date, the -orange spores which precede or accompany the species in the present -genera. Already Tulasne and some others accord them no place in their -system. - -It may be added, for the benefit of any who wish to pursue the study of -this interesting branch of Cryptogamic Botany, that the leaves of the -plants containing the parasitic fungi now noticed may be collected and -preserved by drying between folds of blotting-paper, or the leaves of a -book, and will retain their character, with the exception of colour in -the orange forms, so as to be eligible for examination at any period of -the year for twenty years to come. Each species, when dry, may be -transferred to an old envelope, and labelled outside with the name, date -of collection, and locality; and one hundred such envelopes will -constitute a miniature herbarium in a very small compass. - - ------------------------------------------------------------------------- - - - - - CHAPTER VI. - - _SMUTS._ - - -ONE of the fungal diseases of corn long and widely known has obtained -amongst agriculturists different appellations in different localities. -In some it is the “smut,” in others it is respectively “dust-brand,” -“bunt-ear,” “black-ball,” and “chimney-sweeper,” all referring, more or -less, to the blackish soot-like dust with which the infected and -abortive ears are covered. This fungus does not generally excite so much -concern amongst farmers as the other affections to which their -corn-crops are liable. Perhaps it is not really so extensively -injurious, although it entirely destroys every ear of corn upon which it -establishes itself. Wheat, barley, oats, rye, and many grasses are -subject to its attacks, and farmers have been heard to declare that they -like to see a little of it, because its presence proves the general -excellence of the whole crop. No one who has passed through a field of -standing corn, after its greenness has passed away, but before it is -fully ripe, can have failed to notice, here and there, a spare, -lean-looking ear, completely blackened with a coating of minute dust -(Plate V. fig. 98). If he has been guilty of brushing in amongst the -corn, it will still be remembered how his hands and clothing became -dusted with this powder; and if at the time he should have been clad in -sombre black, evidence will have been afforded—in the rusty-looking tint -of the powder when sprinkled upon his black continuations—that, however -sooty this powder might appear whilst still adhering to the ears of -corn, it has an evident brown tint when in contact with one’s clothes. -This powder, minute as it is, every granule of it constitutes a spore or -protospore capable of germination, and ultimately, after several -intermediate stages, of reproducing a fungus like the parent of which it -formed a part. During the growth of the plant its virulent contents flow -like a poison through the innermost tissues, and at length attack the -peduncle or axis of the spikelets of the ear, raising up the essential -organs and reducing them to a rudimentary state. Brongniart, who made -this species the special subject of observation, states that the fleshy -mass which is occupied by the fungus consists entirely of uniform -tissue, presenting large, almost quadrilateral cavities, separated by -walls, composed of one or two layers of very small cells filled with a -compact homogeneous mass of very minute granules, perfectly spherical -and equal, slightly adhering to each other, and at first green, -afterwards free or simply conglomerate towards the centre of each mass, -and of a pale rufous hue; at length the cellular walls disappear, the -globules become completely insulated, and the whole mass is changed into -a heap of powder, consisting of very regular globules, perfectly alike, -black, and just like the reproductive bodies of other fungi (Plate V. -fig. 99). A scientific botanist of some repute, M. Unger, published a -work in Vienna during the year 1823, in which he sought to prove that -this, and allied species of fungi, were not fungi at all, but merely -broken up cells, or disruptured and altered conditions of certain -portions of the diseased plants. The most satisfactory refutation of -this theory may be found in the fact that the spores of the smut can be -seen to germinate under favourable conditions, and produce fruit, -whereas, if they were only the ordinary cells of the plant broken up by -disease, fructification would not take place. - -The spores in this species are exceedingly minute. It has been -ascertained that forty-nine of them would be contained within a space -the one-hundred-and-sixty-thousandth part of a square inch; hence one -square inch of surface would contain little less than eight millions. -These myriads of spores are shed from the ears, and nothing remains but -the barren matrix in which they were borne when the farmer proceeds to -gather in his crops. At that time he sees no more of the “smut,” all -remembrance of it for the time is gone, his only thought is to stack his -corn in good condition. But the millions of spores are dispersed, ten -millions at least for every ear that has been “smutted,”—and will they -not many of them reappear next year, and thus year after year, with as -much certainty as the grain upon which they are parasitic? - -Like many of the parasitic fungi, so destructive in the farm and the -garden, this species belongs to the family in which the spores are the -distinctive feature. After many botanical changes, the “smut” is at -length regarded as a fixed resident in the genus _Ustilago_; with the -specific name of _segetum_, which latter signifies “standing corn;” it -is therefore the _Ustilago_, or _smut of the standing corn_. The -characters of the genus are, chiefly, that the spores are simple and -deeply seated, springing from delicate threads, or in closely-packed -cells, ultimately breaking up into a powdery mass. Fifteen members of -this genus have been described as British. One of these (_U. maydis_) -attacks the maize or Indian corn grown in this country in a similar -manner as the common smut attacks wheat or barley; but as maize is not -an established crop with us, a more minute description of this species -is unnecessary; the spores are figured in Plate V. fig. 108. Another -species (_U. hypodytes_) makes its appearance at first beneath the -sheaths of the leaves surrounding the stems of grasses (fig. 100), and -ultimately appears above and around them as a purplish-black dust (fig. -101). The seeds of sedges, the leaves and stems of certain definite -species of grass, the flowers of scabious (Plate VI. figs. 123-125), the -receptacles of the goatsbeard, the anthers of the bladder campion, and -other allied plants, and the seeds of the Bistort family, are all -liable, more or less, to the attacks of one or other of the residue of -the fifteen species of _Ustilago_ already referred to as indigenous to -Britain. - - -[Illustration: - - Plate V. - W. West imp. -] - - -Although we do not profess to teach practical men how to grow good corn, -or how they shall get rid of, or keep clear from, the many foes to which -their crops are exposed, yet a suggestion may be offered, based upon the -facts obtained in our botanical researches, supported by the analogy of -allied circumstances. In this instance the extreme minuteness and -profusion of the spores would evidently render all the corn liable to -the attachment of, perhaps only two or three, spores to the seed coat. -Some ears of corn in nearer proximity to the smutted ears may be covered -with spores which yet remain invisible to the naked eye, and when these -grains are mixed with others in the heap, the chances are not much in -favour of any handful not becoming charged with spores. If the majority -of these were not redeemed from destruction by the many changes, -shiftings, rubbings, and scrubbings to which the seed corn is liable -between the time of its reaping and the period of its sowing, we might -expect a very large crop of “smutted” corn. Under ordinary circumstances -we can scarcely imagine that the loss arising from infected ears would -repay much special labour to prevent it, only that to a large extent the -precautions taken to cleanse the seed corn from the spores of one fungus -will also avail for another, and while cleaning it of the spores of -“smut,” those of “bunt” will also be removed. The facts that we rely -upon chiefly as indicating the remedy are that the spores are only -superficially in contact with the seed corn, and that they are of less -specific gravity, causing them to float on the surface of any fluid in -which the corn may be immersed. Again, the spores of many species of -fungi will not germinate after saturation with certain chemical -solutions. One of the most successful and easy of application is a -strong solution of Glauber’s salts, in which the seed corn is to be -washed, and afterwards, whilst still moist, dusted over with quick-lime. -The rationale of this process consists in the setting free of caustic -soda by the sulphuric acid of the Glauber’s salt combining with the -lime, and converting it into sulphate of lime. The caustic soda is fatal -to the germination of the spores of “bunt,” and probably also of “smut;” -although, as already intimated, except in cases where these affections -of the corn are very prevalent, we shall be informed by the -agriculturist that the cost of labour in the prevention will not be -compensated in the cure. - -Experience has also taught us that many fungi flourish in proportion to -the wetness of the season, or dampness of the locality. A wet year is -always exceedingly prolific in fungi, and a dry season correspondingly -barren, at least in many kinds, whilst others, as the experience of 1864 -has convinced us, are exceedingly common. In a field or wood the -mycologist reaps his richest harvest of mycological specimens in the -lowest and dampest spots, in swamps, ditches, and ill-drained nooks. -This is a fact worth knowing as much by the farmer as the amateur -botanist in search of specimens for his herbarium. - -One of the most unmistakable species of “smut” is that which infests the -goatsbeard, on which we have already described an _Æcidium_. Generally -about the same time as the cluster-cups make their appearance on the -leaves, some of the unopened flower-heads of this plant will be found -considerably altered in appearance by the shortening of the segments of -the involucre, and at length by the whole inflorescence being invested -with a copious purplish-black dust. If, by any means, the lobes of the -involucre are any of them separated, the enclosed dust escapes, -blackening the fingers and clothing of the collector, as if it were soot -(Plate V. fig. 92). A little of this dust submitted to the microscope -will be found to consist of myriads of small globose spores, nearly -uniform in size and shape; and if a higher power be employed, each of -these will appear to have a papillose or minutely granulated surface. -The florets, dwarfed in size and contorted, or the remains of them, are -embedded in the mass of spores (fig. 93), and if one or two of these are -removed and placed under a good one-inch objective, every part will be -found covered with adhering spores, to the apparent exhaustion of its -substance. Of course, the florets are never developed when subjected to -the attack of “smut.” The whole plant assumes a faded, sickly -appearance, even before the spores are fully ripened. We would recommend -our readers, if they collect one of the infected flower-heads, to put it -into a box or paper by itself, for if placed in the box with other -specimens it will so sprinkle them with its black powder as to render -them nearly useless for microscopic examination: everywhere the -microscope will detect, where the unaided eye failed to recognize a -trace, the ubiquitous spores of _Ustilago receptaculorum_ (Plate V. fig. -94). - -In the fenny districts of the eastern counties a species of “smut” -called _Ustilago typhoides_ attacks the stems of reeds, forming thick -swollen patches of several inches in length (fig. 128), sometimes -occupying the whole space between two joints or nodes, and lying beneath -the sheath of the leaves. The spores in this species are larger than in -the species which attacks the culms of grasses in a similar manner -(Plate VI. fig. 129). - -There are not many features in the rest of the species of this genus of -sufficient interest to the general reader or microscopist to render it -advisable to furnish any detailed account of them. We may, however, note -that in a species found on the leaves of the common cock’s-foot grass -the spores are large, obovate, and rough, with minute granules (figs. -117, 118). This species is known botanically as _Ustilago_ _salveii_, -and externally bears considerable resemblance, except in the size and -colour of the spores (fig. 119), to another species much more common, -and which occurs on the leaves of _Poa aquatica_ and _P. fluitans_. The -last-named species forms long parallel sori, extending often for several -inches along the leaves of the aquatic grasses just named, giving them a -very singular appearance (Plate V. figs. 105, 106). The spores are small -(fig. 107), not being more than one-fourth the length of the last -species, and smooth, whilst those are minutely granulated. - -An interesting species occurs, very rarely, on the stems of such grasses -as _Aira cæspitosa_ and _A. aquatica_. The sori are in bands at regular -distances apart (Plate VI. fig. 120), each band being composed of a -number of short parallel sori (fig. 121). The spores are not more than -one-third of the size of those in _U. longissima_. - -Sedges are also subject to attack from other species of smut; one of -these (_U. olivacea_) appears to convert the seeds into a fine -olive-coloured dust (Plate VI. fig. 126), which gives to the fruit a -similar appearance to that presented by corn when attacked by _Ustilago -segetum_. Another species, which also absorbs the seeds, becomes -hardened and consolidated more than in any other species, and, though -larger than the normal seeds, still retaining their form (figs. 109, -110). This is _Ustilago urceolorum_, the spores of which are also -figured (fig. 111). - -The beaksedge (_Rhyncospora alba_) suffers from an allied species which -affects it in a similar manner (Plate V. figs. 96, 97), but is not -equally common. The spores of _Ustilago utriculosa_, found on different -species of _Polygonum_, instead of being granulated, are reticulated on -the surface (Plate VI. figs. 114, 116). The chief interest attaching to -_Ustilago antherarum_ consists in its habitat, for it is developed in -the anthers of the flowers of the bladder campion, and other plants of -the same natural order. The anthers are much swollen and distorted by -this parasite, which is not uncommon, though easily overlooked unless -specially sought after (Plate V. figs. 102-104). A list of all the -British species will be found at the close of this volume. It will be -noted that as in the genus _Æcidium_ the prevailing colour of the spores -is orange, so in the genus _Ustilago_ it is black, with a purplish or -violaceous tinge. - -Four diseases in wheat of fungal origin are known and recognized in the -popular language of the farm as “mildew,” “rust,” “smut,” and “bunt.” -Sometimes one and sometimes another is most prevalent, and he is an -exceedingly fortunate individual who can walk through his fields and -find only one of them, especially if that one should be sparingly -distributed. It has been our good fortune to dwell much amongst -cornfields, and the terror of the word “mildew” to a farmer’s ears is -not unfamiliar in our reminiscences of the past, ere we discarded the -much-loved country to become a dweller in town. The subject of our -present remarks inspired no such alarm in the districts of our -experience, but in some seasons and localities it is certainly one of -the “pests of the farm.” Under the different appellations of “bunt,” -“pepper brand,” “bladder brand,” and sometimes “smut,” this infection is -very generally known. Externally there is no appearance, except to the -practised eye, that anything is wrong. There is no black impalpable dust -about the ears as in the true “smut,” no red withered leaves or spotted -stem as in the “rust” and “mildew,” and no stunted growth or -malformation, evident to the casual glance, by which the insidious foe -can be recognized; but stealthily and secretly the work is accomplished, -and until the “bunted” grains make their appearance in the sample, the -disease may, perchance, be unchallenged. - -Externally the “bunted” grain is plumper, and whilst the corn is still -green these will be of a brighter green than the rest (Plate V. fig. -84). When broken, the farinaceous interior will be found replaced by a -minute black dust of a very fœtid, unpleasant odour, and greasy to the -touch (fig. 85). This powder constitutes the spores of the “bunt” mixed -with myceloid threads. It may happen that much of the corn in a field is -“bunted,” and the discovery not made till the wheat is being ground for -flour; then the odour and colour will speedily decide the produce to be -unfit for human food. We have not the least doubt that “bunted” corn, -when ground with flour, is injurious in proportion to its extent, whilst -at the same time we can scarcely conceive an intelligent miller grinding -up a sample containing any large proportion of “bunted” grains in -ignorance of the fact. - -If we break open a grain of wheat infested with the “stinking rust” or -“bunt,” and then place some of the powder in a drop of water on a glass -slide, and submit this to the microscope, first using the half-inch -power, then the quarter, or fifth, and finally an eighth or tenth, we -shall find that this minute dust consists of myriads of globose brown -bodies termed spores, which possess certain reproductive functions. -These spores will be found mixed with a number of delicate branched -threads, to which they are attached by a short stalk or pedicel, visible -with the higher powers (fig. 86). The surface of the spores you will -also observe to be beautifully reticulated. These features just -described as visible in the “bunt” are the characteristics of the genus -to which it belongs (_Tilletea_), and of which it is the only British -species. An allied species infests the Sorghum or durra, a grain but -little cultivated in Europe, but found extensively in Africa and Asia, -and also apparently found on the _Bajra_ of India. - -The interesting experiments of the Rev. M. J. Berkeley on the -germination of “bunt” spores have been already alluded to. They were -undertaken shortly after the outbreak of the potato disease, to -ascertain, if possible, the mode by which the minute spores of fungi -inoculate growing plants; and although at that time only a bare -suspicion of the nature of the bodies resulting from the germination of -“bunt” spores was entertained, succeeding examinations in the same -direction have brought to light extraordinary facts, and manifested the -progress of the successive developments of four generations. The spores -of “bunt” are larger than those of the different species of “smut,” and -reticulated on the surface (Plate V. fig. 86). When these are made to -germinate a kind of stem is protruded (fig. 87), upon which small -clusters of elongated thread-like spores of the second generation, or -sporidia, are produced (fig. 88). After a time these spores conjugate, -or become united by short transverse processes in the same manner as has -been observed in some of the lower forms of Algæ (fig. 89). The -conjugated spores in the next stage germinate and produce a third kind -of fruit, different from either of the preceding, and constituting a -third generation (fig. 90). These in turn germinate and produce a fourth -order of reproductive organs (fig. 91), so that in the process of growth -the “bunt” spores evidently pass through four generations. Hence, as one -result, the number of germinating bodies is greatly increased, as well -as their power of inflicting injury in a corresponding diminution in -size. There are still many points in the history of the growth and -development through successive generations of the “bunt” spores, but -enough is known, on the one hand, to show that this is a true vegetative -parasite, and not merely a diseased condition of the tissues of the -wheat plant, and on the other that it is perfectly distinct from all the -phases of the other and similar parasitic fungi which affect the wheat -crop. - - ------------------------------------------------------------------------- - - - - - CHAPTER VII. - - _COMPLEX SMUTS._ - - -SOME of the microscopic fungi are the most unpromising and uninteresting -objects to the naked eye which could well be imagined. No one would -suppose that the black dust so profusely shed in such genera as -_Ustilago_ and _Polycystis_ could be better than as much soot; unless he -has learnt by experience not to judge by appearances, but to suspend -judgment until examination. The axiom will sooner or later force itself -upon all who examine minute objects with the microscope, that all -organic nature, whether animal or vegetable, increases in interest in -proportion to the magnifying power. Seen by the unaided eye, _moulds_ -are all nearly alike, and they seem to be “moulds” and nothing more. -“Smuts,” again, sometimes attack one organ, and sometimes another, with -very little variation in colour; and “rusts” are all “only rusts” with a -paler or more intense rusty tint, until the marvellous combination of -lenses, so appropriately named a _microscope_, unfolds a new world, and -exposes its new inhabitants unparalleled in the old world of larger -life, in form, habit, development, and mystery. - -A very interesting, though small group of fungi, allied to the -preceding, are included botanically under the genus called _Polycystis_, -in allusion to the many cells of which the spores are composed.[6] In -the most recent work on British Fungi, approximating to a Flora—viz., -“Berkeley’s Outlines”—only three species are recorded, whilst the most -common, at least around London, is omitted in error; for it could -scarcely have been unknown as indigenous to this country. This last is -the crow-foot smut (_Polycystis pompholygodes_, Lev.), found on the -leaves and petioles of the common creeping buttercup (_Ranunculus -repens_), distorting them very much, and also occurring on the -wood-anemone and some other Ranunculaceous plants. The leaves and their -footstalks, when attacked, become swollen, as if blistered at first, and -ultimately burst in an irregular manner, exposing a mass of blackish -soot-like dust (Plate IX. fig. 183), which on examination will be found -to consist of the many-celled spores alluded to (Plate IX. fig. 184). -Each of these spores appears to have a transparent outer membrane, -either enclosing an unequal number, from two or three to five or six, -distinct cells, compressed together into a spherical form by the outer -integument, or the interior is divided by septa into as many cells. Each -of these divisions contains a dark brownish endochrome, or -cell-contents. As may be anticipated, the spores in all the species -associated in this genus are interesting objects for the microscope. The -species on the buttercup may be found through the summer and autumn on -_Ranunculus repens_, especially whenever that plant is met with in very -damp situations. We have seldom found the plant in any profusion without -its attendant fungus. - -Footnote 6: - - Rabenhorst has proposed _Urocystis_ as the name of this genus, on the - ground that _Polycystis_ was priorly applied to a genus of Algæ. - -Another species of these many-celled smuts is not uncommon in gardens, -on the sweet violet, attacking the footstalks of the leaves more -commonly than the leaves themselves, and swelling and contorting them -(Plate IX. fig. 185). In general structure the spores are very similar -to those of the last species, save that the cells are smaller, and a -larger number are collected together (Plate IX. fig. 186). So far as we -have yet examined the spores of this and the preceding species, they -appear to consist of separate and distinct vesicles (probably spores), -contained within a hyaline sac or outer membrane, and _not_ to be a -single spore divided into cells by numerous septa. - -A species of equal interest (_Polycystis Colchici_, Tul.) is found on -the autumnal crocus, or meadow-saffron (_Colchicum autumnale_). The -spores approach nearer to those of the last than of the prior species. - -A fourth species occurs on the leaves of rye (Plate IX. fig. 187), -forming elongated parallel blackish lines (_Polycystis parallela_, B. & -Br.). It has also been found on the leaves of some grasses, but does not -appear to be very common. - -Many similar features are possessed by the two members of a genus named -_Tubercinia_, which have been found in this country. One of the species -is parasitic upon a plant which we who inhabit southern England never -meet with, but which is not uncommon in Scotland, _i. e._, _Trientalis -Europæa_. The parasite attacks the leaves about the month of September, -forming bullate or blistered patches one-eighth to one-sixth of an inch -broad, containing a mass of black spores (Plate III. fig. 52). These -spores are irregularly globose, large, and opaque, consisting of a -number of distinct cells (Plate III. fig. 53). Never having seen other -than dried specimens—kindly communicated by Dr. Dickie of Aberdeen, the -discoverer of this species—we cannot add much to its history beyond the -published description by the Rev. M. J. Berkeley. - -The other species occurs on potatoes, and is, during some seasons, -common in all parts of Great Britain. The spores are curious, being -composed of a number of cells arranged in the form of a hollow sphere, -with one or two apertures communicating with the interior (Plate III. -fig. 54). They are generally attached by a delicate thread. This -species, sometimes confounded with the potato scab, was first described -by Mr. Berkeley, about the time of the appearance of the “potato -disease,” with which, however, it is in no way connected. - -Thus it will be seen that, inasmuch as we have complex brands in which -the number of cells are considerably increased, so have we “complex -smuts” in which, instead of one cell, we have many. In the last instance -the two genera associated together in this chapter agree. The spores in -both are distinctly cellular, but in the last genus far more opaque and -consolidated than in the first. Whilst it may be doubted whether the -compound spores of _Polycystis_ are anything more than a number of -individual spores with a gregarious habit, invested with an outer -membrane, such a hypothesis cannot (as far as our individual -examinations extend), be made to include _Tubercinia_. No doubt has yet -been thrown on the genuine character of either of these genera. No -_Uredo_ or _Æcidium_, no _Trichobasis_ or _Puccinia_ has been -ascertained or suspected to appear as a prior or subsequent form. In -their supposed integrity they offer an interesting study, and in their -development a good subject for investigation. - - ------------------------------------------------------------------------- - - - - - CHAPTER VIII. - - _RUSTS._ - - -UNFORTUNATELY, this group of fungi contains species but too well known -for their ravages amongst graminaceous plants, especially the cereals. -“Corn rust,” as it is generally called, has a reputation little better -than mildew, and it really deserves no better, for it is only another -form of that pest of the farm, from the mycelium of which the -corn-mildew is at length developed. There are two species very closely -allied (doubtless only forms of the same species with different spores) -which attack the leaves and culms of growing corn, and, bursting through -the cuticle in the manner represented in Plate VII. fig. 141 -(magnified), give a peculiar rusty appearance to the plant, as -represented in Plate VII. fig. 140. One of these corn-rusts is -botanically named _Trichobasis rubigo-vera_ (Lev.), or the “true rust -_Trichobasis_;” the latter, which is the generic name, being a compound -of two Greek words (_thrix_, a hair, and _basis_, a foundation), on -account of the spores being at first furnished at their base with a -short, thread-like peduncle, which at length falls away (Plate VII. fig. -142). The other Corn rust is _Trichobasis linearis_, or “line-like -_Trichobasis_,” because the sori or pustules are linear, or lengthened -out like a line; the spores nearly double the length of those of the -other Corn rust (Plate VII. fig. 144), and not so bright in colour. By -intermediate forms these two rusts pass insensibly the one into the -other, so that it is sometimes difficult to distinguish them. Both have -the spores clustered together in the pustules, at first (Plate VII. fig. -143) attached by their peduncles, but they soon become free, and are -scattered like rust-powder over the plant. Adverting to the attack of -rust upon the wheat crops to an unusual extent a few years since, the -Rev. M. J. Berkeley wrote as follows:— - - We have seen rust more prevalent in white wheats, especially in - the variety called Russian white, which has red smooth chaff, - than we ever remember it. It is, however, confined to particular - spots; and while in one field not a single leaf is free, - insomuch that a person walking through the wheat is completely - painted with the spores, of a fine rust-red; an adjoining field, - separated only by a hedge, has not a rusty leaf. So long, - however, as the rust is confined to the leaf, it is, we believe, - perfectly harmless. The grain swells in spite of it, and the - only effect is that the flag dies a little earlier, which is not - undesirable when it is too luxuriant. If, however, it gets to - any extent upon the chaff, much more if it attacks the seed - itself, as is sometimes the case, it is very mischievous. - - -[Illustration: - - Plate VI. - W. West imp. -] - - - There is, indeed, a notion that rust is merely a form of mildew, - and this may be true; but if so, it is a harmless form. The true - rust (_T. rubigo-vera_), if a form of mildew, preserves its own - characters to the end, and merely presents a second form of - fruit, a circumstance which is exceedingly common amongst the - lower fungi. It may exist in company with the mildew, but it - also more frequently is developed without a trace of mildew - intermixed. As far, then, as its immediate effects upon the - plant go, it may be treated as a distinct parasite, though - advanced botanists may look upon it as offering a case of what - they call dualism, which may be easily understood on a - comparison with such plants as marigold and orache, which - produce seeds of two different forms. Its ultimate effects may, - indeed, be injurious, as, if it be really a second form of - mildew, it is capable of propagating that pest. The case is - quite different with _Trichobasis linearis_, which is in fact - merely the young state of the mildew. When once that supposed - species makes its appearance, it is quite certain that there - will be mildew to a greater or less extent. While the spores of - the one remain unaltered, though intermixed with the true - bipartite spores of the mildew, the other exhibits every - intermediate state of form and colour. - -M. Tulasne, to whom we have already alluded as a high authority on this -subject, is of opinion that all the species enumerated in this group or -genus, are mere conditions of other species, and therefore excludes it -altogether. Another genus (_Lecythea_), for the same reason, has shared -the same fate. - -It must not be forgotten that twenty-eight species of rust belonging to -this genus are now recorded as occurring in Great Britain. Some of these -have yellow or yellowish spores; the rest have the spores of a decidedly -brown colour. One of the most attractive of the yellow-spored species is -that which appears on the groundsel (_T. Senecionis_), and a good notion -of its external appearance may be gained from our figure (Plate VII. -fig. 145). It is not always to be found without searching closely, for -in some localities we have found it very sparingly, whilst elsewhere—as, -for instance, on Wandsworth Common—we have met with it as soon or as -late as there were groundsel leaves for it to grow upon. No spot or -change in the appearance of the upper surface of the leaves indicates -the presence of the parasite beneath; this is, however, often betrayed -by the golden-yellow streaks which appear on the stem. Many a time and -oft the boys in the semi-rural districts about town have marvelled and -questioned each other concerning the reason why, in gathering -“groundsel” for the little bird at home, we should be so particular, and -pass so many promising plants, plucking here and there a leaf, and -seldom collecting one which they consider eligible for the purpose. -Collectors of minute fungi must expect to overhear occasionally even -hints touching their sanity from those who, without the remotest idea of -their mission, think they must be slightly “wrong in the head” to gaze -so narrowly and intently, amongst nettles, groundsel, grass, or dry -leaves, and only take an occasional fragment of a rotten stick, or two -or three sickly leaves, carefully deposit them in their wallet, hat, or -pocket, and then “move on.” - -It will be unnecessary to repeat what has been stated in a former -chapter on spermogones. It will be remembered that these organs are -found developed in connection with some of the species of the present -genus, as well as with the cluster-cups, or _Æcidiacei_. They consist -externally of small conical elevations, pierced at the apex, which -contain minute, cellular, linear bodies called spermatia, invested with -a kind of mucous substance, that over-flows with them from the orifice -of the spermogone, like lava from the crater of a miniature volcano. The -rust in company with which they have been found most plentifully, is -that which covers the under surface of the leaves of the commonest of -all thistles (_Cnicus arvensis_). The external form of one of these -spermogones is figured Plate VII. fig. 153. The rust possesses, when -fresh, a peculiar odour, which is said to resemble that of -orange-flowers; whence was derived its name of “sweet-smelling rust” -(_Trichobasis suaveolens_, Lev.). M. Tulasne writes:—“With respect to -this species, it is, in my opinion, but the first form of a _Puccinia_, -analogous to _P. Compositarum_, D.C.: the spermogones with which it is -mixed being very abundant, it ought to be placed with that _Puccinia_. I -should, perhaps, retain some doubts upon the legitimacy of this -relationship, if it had not been my fortune to meet on another species -of the same kind (_Puccinia Anemones_, P.) spermogones perfectly -characterized, and in which the colour, habit, and position would not -allow me to hesitate an instant in attributing them to the _Puccinia_.” -In this species of rust the whole under surface of the leaf is covered -with a purplish-brown dusty coating of the spores, from the numerous -pustules which are produced (Plate VII. fig. 151). The plants, when -attacked, have a paler and more sickly appearance; the leaves have a -tendency to fold backwards at their margins, and thenceforth their -growth seems to be determined. Sowerby, in his “British Fungi,” -says:—“Two or three sorts of flies are occasionally found dead on this -plant at the time of the fungus being upon it, which is after wet -weather in the summer, or early in autumn; being apparently tempted by -its flavour, they over-eat themselves, or else are destroyed by some -poison.” This rust has spores resembling, in general characters, those -of the yellow-spored series Plate VII. fig. 152). - -We have not thought it necessary to give figures of many species, partly -on account of the uncertainty existing in many minds whether they ought -to be regarded as species, and whether they will long claim a place in -the British Flora; and partly on account of the similarity which exists -between them, at least so far as they are of interest to the -microscopist only. - -During the autumn of last year, whilst on a botanical excursion through -a portion of Epping Forest, the “great bog” became a centre of some -interest. Bogs are generally attractive spots to those who are in search -of microscopic organisms. On this occasion the chief objects of interest -were the small brown pustules (Plate VIII. fig. 168) with which the -upper surface of a large number of the leaves of the pennywort -(_Hydrocotyle vulgaris_) were sprinkled. These pustules were brown, -orbicular, regular, and in habit seemed to resemble rather those of most -of the _Pucciniæ_ than of a _Trichobasis_. The large, vigorous, and -healthy leaves were less affected. Microscopical examination, at first -incomplete, led us to the conclusion that it was a species of _Uredo_, -which had been met with in France (_Uredo Hydrocotyles_, Mont.); but a -re-examination, to which we were prompted by Mr. Currey, led to the -conclusion that it belonged rather to the present genus; but it can -scarcely be associated with any species already described, -notwithstanding its apparent affinity with the brown rust found on -umbelliferous plants, in which the pustules are invariably developed on -the _under_ surface. Under these circumstances, we have called it the -Pennywort rust (_Trichobasis Hydrocotyles_), whilst still doubtful -whether it is not the same fungus as that described by Montagne, with -whose description it agrees in everything, except what is implied by the -generic name. It should not be forgotten, that the work in which -Montagne first described this species was published when the genus -_Uredo_ embraced the present genus, which was separated from it by -Leveille twelve years later; and it is possible that this species was -included in a more recent work by the same author, in error and without -re-examination, under the old name. An examination of authentic -specimens of Montagne’s plant would settle the point; but we know of no -published collection which contains it. The characteristic difference -between the two genera lies in the presence of a peduncle in the early -stage of _Trichobasis_ Plate VIII. fig. 169), and its absence in all -stages of _Uredo_. Without wandering further into a subject which has -not the merit of being very popular, let us away to some green lane in -search of violets, and having found them, take a little of the brown -dust from one of the small pustules on the leaves, upon the point of a -penknife; place this, with a drop of water, upon a glass slide, and make -a record of what we observe. - -The field is covered with the myriad spores of a rust of a nearly -spherical shape, brownish in colour, and here and there one with a short -transparent colourless stalk or pedicel. This is the violet rust -(_Trichobasis Violarum_, B.), very common all through the summer and -autumn, generally on the under surface of the leaves of violets, in -woods and hedgerows. Should it so happen that the spores when placed -under the microscope are found to be two-celled, it will prove that -instead of a rust, or _Trichobasis_, being under examination, a brand, -or _Puccinia_, has been found, which is almost equally common, and which -may, without such a test, be easily mistaken for a rust. According to -the theory of di-morphism, this is the higher form or complete fruit of -the same fungus, which in its simple-celled state is called _Trichobasis -Violarum_. - -A similar circumstance may befall the student in examining the rust of -labiate plants (_Trichobasis Labiatarum_, Lev.), which occurs on -different species of mint, especially the water-mint, about the month of -August. We have found a few of the two-celled spores of the _Puccinia_ -imbedded in the pustules of this rust almost constantly, whilst the -one-celled spores are not uncommon in the pustules of what is regarded -as the true mint brand (_Puccinia Menthæ_, P.). - -In spring the young leaves of the periwinkle (_Vinca major_) will, in -some situations, become thickened considerably, and ultimately browned -on both faces with the pustules of a rust (_Trichobasis Vincæ_), which -though covered with a conidioid dust are often very tardy in bursting -the epidermis. It is almost impossible, after the pustule is ruptured, -to find one in which the bilocular spores of _Puccinia_ (fig. 132) are -not largely intermingled with the unilocular spores of the “rust” (Plate -VI. fig. 131). Later in the season by two or three months, other leaves -of the same plants will be found occupied by the smaller and more widely -scattered pustules of _Puccinia Vincæ_, in which the unilocular spores -of the “rust” will seldom be found. In this instance the leaves are -scarcely thickened, and the colour of the spores is much darker. The -under surface of the leaves is commonly alone occupied, and -corresponding paler spots on the upper surface indicate the presence of -the parasite beneath. - -The garden and field bean is liable in some seasons to become quite -rust-coloured in consequence of the profusion of spores with which the -leaves and stems are covered, from the bean rust (_Trichobasis Fabæ_, -Lev.), which in like manner is considered as the simple stage or form of -the bean brand (_Puccinia Fabæ_, Lk.). If the legumes are also examined, -a few pustules will sometimes be found on them. Beans thoroughly -infected with this rust or brand are seldom of much service in either -field or garden. - -Beetroot, or mangold wurzel, is another example of garden and field -produce which is subject to a similar visitation. This rust often has -very red spores when produced on red varieties of beet. During -September, 1863, it (_Trichobasis Betæ_, Lev.) was sent us on the leaves -of the wild beet (_Beta maritima_). - -All the species of _Polygonum_ are exceedingly subject to the attacks of -the Persicaria rust (_Trichobasis Polygonorum_, B.), which nearly covers -the leaves, till the entire plants seem to be smothered in Scotch snuff. -If it were allowable to affirm of any plants that they are martyrs to -parasitism, such might be said of the Persicarias and their allies. - - -[Illustration: - - Plate VIII. - W. West imp. -] - - -Sedges are subject to the attacks of a rust much resembling the corn -rust. When it occurs on some species of _Carex_, the upper surface of -the leaf has corresponding pale spots, and the pustules themselves are -surrounded by a yellowish margin. This species (_Trichobasis caricina_) -is far from uncommon (Plate VIII. figs. 170, 171). The sedge-like plants -belonging to the genus _Luzula_ have also their own species of rust -(_Trichobasis oblongata_), the spores of which are deeper in colour than -in the sedge rust (Plate VII. figs. 158, 159). - -Amongst the remaining species of _Trichobasis_ (the reader must pardon -our using the generic name, as we have no equivalent), that found on the -leaves of various composite plants is the most common (_Trichobasis -Cichoracearum_, Lev.). It occurs on some thistles, on the saw-wort, -dandelion, several species of hawkweed, and similar plants. The pustules -are small and more diffused than in the species found on _Cnicus -arvensis_, and they as often appear on the upper as on the lower -surfaces of the leaves. - -On umbelliferous plants three species are recorded; one with yellow -spores (_Trichobasis Petroselini_, B.); another with a blistered habit, -and brown, ovate, or oblong spores (_T. Umbellatarum_, Lev.); and a -third with tawny, obovate, or egg-shaped spores (_T. Heraclei_, B.), -which is found solely on the cow-parsnip. The species of _Puccinia_ -corresponding to some of these species of _Trichobasis_ are known, but, -in other cases, probability, or speculation if you please, occupies the -place of knowledge. - -During the month of September, 1864, it was our good fortune to spend a -week in revisiting the scenes of our boyhood, and exploring the minute -botany of one of the marshy districts of East Norfolk. One day of the -seven, memorable to us for the discovery of three specimens of a large -Boletus (_B. cyanescens_),[7] not found, to our knowledge, since the -days of Sibthorpe, was further enriched by a species of _Trichobasis_, -new to Britain, and apparently uncommon on the Continent. This rust was -found on the leaves of the “grass of Parnassus” (_Parnassia palustris_) -on a narrow strip of marsh near Irstead church. It was sought in vain -elsewhere. The leaves were scarcely changed in appearance, except by the -presence of the pustules. There were no discoloured spots, but the -pustules appeared sometimes plentifully, more often scattered, on both -surfaces of the leaves: they were small, of a bright brown, with oval -spores; the latter were, in their early stages, shortly stalked. We have -called this species _Trichobasis Parnassiæ_. It is possibly the same as -published by Westendorp in his “Herbier Cryptogamique Belge” as _Uredo -Parnassiæ_, but we know of no copy which we can consult, and have failed -in discovering any other species to which we can refer it. It is -certainly a _Trichobasis_ and not an _Uredo_, according to the present -limitation of the latter genus. - -Footnote 7: - - Two of these specimens were found at the bottom of a hedge-bank, - amongst grass, by the side of the road leading from Neatishead-street - to Irstead Rectory, and the third in a similar position by the Norwich - road, two hundred yards from the turning which leads to - Neatishead-street. - -Although the evidence against the retention of the species of _Lecythea_ -(as the genus is named) amongst Fungi as true species, on the ground of -di-morphism, is even stronger than against the group just illustrated, -we cannot pass them altogether in silence, especially in a popular -treatise. Those who are residents in town, and yet possess their little -plot of garden-ground, with only two or three pet roses, may have had -the misfortune of seeing them smothered with a yellow blight. This -golden visitation, unwelcome as it is, may afford a subject for the -microscope, and for a small space in this chapter. At first there will -not appear to be any important difference between the spores of the -yellow series of the last genus and those of the present; but a closer -examination will reveal one important distinction, viz., the presence of -colourless elongated, abortive spores. The species are not so numerous -by half as those of _Trichobasis_, even when three anomalous forms are -included, which species are included by some mycologists in two other -genera. One very common rust of this group has already been alluded to -(Plate II. fig. 37), and which is known botanically as _Lecythea Rosæ_. -A similar one is found on the bramble, and another on the burnet. All -these three species are produced at first on spots which are afterwards -more or less occupied by the long, many-celled spores of the dark brown -brands called _Aregma_ or _Phragmidium_, between which and the simple -yellow spores of the rust almost every intermediate form may often be -found in the same pustule. Thus, from the same mycelium as that of the -rose rust, the rose brand is afterwards developed; whilst from the nidus -of the bramble rust (Plate III. fig. 40) the bramble brand is also at -length produced; and the successor to the burnet rust (Plate III. fig. -31) is the burnet brand. Besides these, a rust belonging to the same -genus may be found on the leaves of the poplar, the spurge, and the -common valerian, and two or three species on willows. It can scarcely -have escaped notice, that the goat-willow is almost constantly afflicted -with a rust on the under surface of the leaves (Plate VIII. fig. 160). -This species will again come under notice as the summer spores of a -truly dimorphous species. - -One of the rusts separated by some botanists from this genus is found -(possibly most commonly) on the leaves of the raspberry; but during the -past autumn we have met with it plentifully on the upper surface of the -leaves of one or two species of bramble, and have never seen it growing -on the raspberry, although in all descriptions of the species that is -stated to be its habitat. Even to the naked eye this is so distinct, -that no one could well confound it with any other. It appears very late -in the autumn, and the spots are scattered at some distance apart from -each other (Plate VIII. fig. 162); each spot or pustule forming a ring -(Plate VIII. fig. 163 enlarged) encircling a cluster of spermogones -which occupy the centre. - -Another rejected species (_Lecythea Lini_, Lev.) occurs on the little -purging flax (_Linum catharticum_), forming small pustules on the leaves -(Plate VIII. fig. 165); these burst irregularly, and remain surrounded -by the remains of the ruptured epidermis (Plate VIII. fig. 166). The -yellowish spores are subglobose (Plate VIII. fig. 167), and in the first -instance concatenate, or chained together like a necklace, which -circumstance has been taken advantage of to place it, with one or two -other species, in a separate genus. - -We cannot claim for the species brought into notice in the present -chapter any attractive features resulting from singularity of form, -complexity of structure, or delicate tracery, whereby they might commend -themselves to mere “searchers after curiosities,” or be recommended from -friend to friend as “sensation” objects for the microscope. They _do_ -possess an interest and a value, but such as would not be appreciated by -those who seek to pass an idle half-hour by gazing at some new thing. - - ------------------------------------------------------------------------- - - - - - CHAPTER IX. - - _RUSTS._ - - -A QUARTER of a century ago, and all the fungi enumerated in the -preceding and in the present and following chapters would have been -arranged under three genera, called respectively _Æcidium_, _Puccinia_, -and _Uredo_. Under the last-named genus all the species illustrated in -the present chapter, beside many others, would have found “a habitation -and a name.” There are still a few which bear the old generic name, and, -if only out of respect, we shall grant them the first place. - -Let the first bright day in May witness the student beside a cluster of -plants of _Mercurialis perennis_, which it will not be difficult to find -in many localities, and, on turning up the lower leaves, he will meet -with our first illustration of a genuine _Uredo_, in the form of yellow -confluent patches, with a powdery surface (Plate VII. fig. 133). This -will be _Uredo confluens_. By the way, the generic name is in itself -suggestive, which it always should be in all instances, but -unfortunately is not; it is derived from the Latin word _uro_, “I burn,” -and is peculiarly applicable in instances where the leaves acquire a -blistered, burnt, or scorched appearance, occasioned by the presence of -the fungus. The microscopical features of the spores of this genus are, -briefly, a more or less spherical form, without any pedicel or footstalk -Plate VII. fig. 134). These spores are at first produced each in a -separate cell, but when ripe become free, and are at times with -difficulty distinguished from such forms as _Trichobasis_, unless the -pedicels in the early stage of the latter genus are regarded. - -A rare species in Britain is the oak-leaf rust (_Uredo Quercus_), in -which the sori or pustules are minute, and at first yellow, but -afterwards orange. It occurs on the under surface of the leaves, and -was, we believe, first found in this country by Mr. D. Stock, in the -neighbourhood of Bungay, nearly five-and-twenty years since. That -gentleman informs us that it was not at all uncommon, but always -appeared on the young shoots which had sprung up from the trunks or -roots of trees that had been cut down. We are uncertain whether it has -been found by any one since that time in this country, although it is -not uncommon in France. - -The leaves of the common sorrel are often sparely sprinkled with the -pustules of a rust (_Uredo bifrons_, Grev.), which derives its specific -name from the fact that the pustules, which appear on both surfaces of -the leaves, are often opposite to each other Plate VII. fig. 137). These -pustules are generally seated on a discoloured spot (Plate VII. fig. 138 -enlarged), and are surrounded by the remains of the ruptured epidermis. -The spores are globose and brown Plate VII. fig. 139). We have not met -with any other _Uredine_ on the sorrel leaves, though one having a -similar appearance to the naked eye is not uncommon on several species -of dock. - -The fern rust (_Uredo Filicum_), which occurs on the under surface of -the fronds of two or three species of ferns, we have never met with, and -do not think that it can be considered common. It has been found in the -West of England, on _Cystopteris_, and Sowerby collected it, probably -not very far from London. - -One of the most common is the rust found on the leaves of the -enchanter’s nightshade (_Circæa lutetiana_), sometimes nearly covering -the under surface with its tawny snuff-coloured spores Plate VII. fig. -135). The plant on which it is found is rather local, but the rust -(_Uredo Circææ_) seems to abound wherever the plant on which it is -parasitic flourishes. Another fungus of a very similar external -appearance may be collected, more rarely, from the leaves of the same -plant; but in this the spores are two-celled, or divided by a transverse -partition. This fact is mentioned to guard against disappointment, -should the spores be found to differ from the characters of this -section, and to show that the microscope is essential to the study of -fungi. The spores of the true Uredo are globose and without any -partition Plate VII. fig. 136). - - -[Illustration: - - Plate IX. - W. West imp. -] - - -We may also observe that a very interesting species may be found on -several species of St. John’s-wort (_Hypericum_), but especially on the -under surface of the leaves of the Tutsan, covering them with its -golden-coloured spores (Plate VIII. fig. 174). Another occurs on the -leaves of some of the wild garlics (_Allium_); one is not uncommon on -some of the stitchworts; another on saxifrages; another on willow-herbs -(_Epilobium_), and one on the leaves of the cowberry. All of these have -yellowish spores. A species with brown spores occurs on sea-lavender -(_Statice_). Space to write on our own part, and patience to read on the -part of others, induce us to dismiss all these species with the bare -allusion to them and the plants on which they may be found. Some of them -may occur in one locality and some in another, and enough has perhaps -been said to enable any one to place any that he may find in the proper -genus, if not with the scientific name. - -From the numerous instances we have met with of persons wholly -disinterested in the subject, collecting and making inquiries concerning -the bright orange patches next to be referred to, we are led to conclude -that most persons have, at least, seen them. These patches of -orange-coloured powder burst through the cuticle, and appear on the -young branches of wild roses, extending sometimes for two or three -inches in length Plate VII. fig. 147), and form one of the most -beautiful and obtrusive of the dust-like fungi. It is not confined to -roses; but the meadow-sweet, on which it is also found, does not grow in -localities where its parasite is so liable to meet the gaze of the -ordinary wayfarer. The habit of this rust is more or less that of those -which are associated with it. The pustules are not small and orbicular -as in most instances in other groups (except _Polycystis_), but are -large and irregular, and generally but few together or single. The -spores are variously coloured, and have peduncles, or footstalks, of a -greater or less length. In the rose rust these spores are profuse, but -the peduncle is short (Plate VII. fig. 148). - -Plants of the pea and bean tribe are liable to be attacked by one of -these rusts, and in this instance the spores are so characteristic that -no one could well confound them with any other. Externally it appears as -an irregular brownish pustule, breaking through the epidermis and filled -with an impalpable powder, not unlike a pinch of “brown rappee” snuff. -The spores are ovoid, with a very long peduncle, whence its name -(_Uromyces appendiculata_). It appears on a great variety of plants, but -from the peculiarity of the spores Plate VII. fig. 150), is easily -recognized. Our figure represents it on the leaf of a vetch (Plate VII. -fig. 149). Almost at the commencement of this volume (Chap. III.) we had -occasion to refer in detail to some experiments made by De Bary on the -spores of this species. In the remarks then made occurs a recommendation -of reperusal, which would obviate any repetition here. - -An allied species, and a beautiful one, is to be found on the stinking -iris (_Iris fœtidissima_), and another on the under surface of the -leaves of primroses. - -The pilewort (_Ranunculus ficaria_) we have already seen attacked by one -species of microscopic fungi, and we have now to record the occurrence -of another. Some plants appear to be destined both alive and dead to -become the prey of others. The common nettle, for instance, as if in -retribution for the annoyance it often occasions on account of its -stinging propensities, has not less than twenty different species of -minute fungi, to say nothing of coleopterous and lepidopterous insects, -which make a home, sometimes upon its green leaves, and sometimes on its -dead stems. We might almost state that it has a flora and a fauna of its -own. The pilewort, too, has many foes; but these are fewer in number, -and mostly attack the living plant. The cluster-cups have been already -noticed; some do not fall within the limits of this volume, but one, -which is found in May and June, belongs to the present genus. It appears -like a purplish-brown powder bursting through blistered spots on the -leaves and footstalks Plate VII. fig. 156). The spores are small, and -are, of course, provided with pedicels Plate VII. fig. 157). - -The under surface of the leaves of the white Dutch clover are often -sprinkled with black spots, which are nearly round and very numerous. -These are so many clusters of fungi belonging to a different section, in -which the threads are the important feature. But another parasite is -also found on leaves of the same plant, in which the pustules are far -less numerous and regular, and are often found on the petiole as well as -the leaf, distorting them and twisting them in various directions Plate -VII. fig. 154). This is the clover rust (_Uromyces apiculata_, Lev.), -which is a parasite on numerous plants, being found also on the great -water-dock and other kinds of dock. The spores are ovoid and brown, with -a short peduncle (Plate VII. fig. 155). A very beautiful species occurs -on the leaves of the ladies-mantle (_Alchemilla_), but hitherto we have -not been fortunate enough to collect it. - -It can scarcely be too great an assumption to suppose that every one is -acquainted with the goat-willow (_Salix caprea_), or that every -schoolboy knows the birch (_Betula alba_). It may be proceeding a step -too far to affirm that all who know these trees well enough to -distinguish the one from the other, will have observed the under -surfaces of the leaves of both sprinkled with a golden dust, during the -summer months, and which are the spores of a parasitic fungus. So common -is this orange-coloured powder on leaves of the trees above-named, that -we can hardly believe any one to have had a branch of either in his hand -and not observed it, provided any leaves adorned the branch in question. -What this parasite is, and what its associates, it is our province to -endeavour to explain. Our figure (Plate VIII. fig. 160) represents a -leaf of the sallow or goat-willow, with the under surface exhibiting -yellow patches, consisting of spores, which are magnified in the next -figure (Plate VIII. fig. 161). This exceedingly common rust is termed -_Lecythea caprearum_, Lev., when in the condition figured; but in -reality this is only the summer stage, bearing the summer fruit of -_Melampsora salicina_, which latter attains its mature development on -the same leaves in the succeeding winter (Plate IX. fig. 191) or early -spring. Of course this latter remark applies to the fallen leaves, for -at this period all the willows and other deciduous trees are bare. But -the leaves, before they fall, give evidence of the parasite at work; and -if the collected decaying mass of rubbish at the base of sallow bushes -be examined about March, these leaves will be found bearing upon them -mature heaps of elongated, wedge-shaped spores, closely packed side by -side (Plate IX. fig. 192), and which, whilst still adherent, may often -be found in active germination, as represented in an allied species at -the bottom of our plate (Plate IX. fig. 197). This phenomenon consists -in the production of cylindrical tubes, more or less elongated, from the -upper extremity (rarely from the base) of the prismatic spores. These -tubes are straight or twisted, simple or forked, and each of them -becomes divided by transverse septa into four unequal cells towards -their apex, from each of which is produced a spicule bearing a -sporidium, or spherical secondary fruit, in the same manner as in the -genera _Puccinia_ and _Aregma_. It should be observed, that the winter -spores of this rust are borne on the opposite surface of the leaves to -the summer spores: for whilst the latter are developed from the under -surface, the former are found on the upper. This being also an instance -of di-morphism, the summer condition, when spherical spores are -produced, should not be regarded as a distinct plant, and the name of -_Lecythea caprearum_ does not merit retention in the list of fungi. - -There are five species of this interesting group, or genus, found in -Great Britain, to the residue of which we may only briefly allude. It -has already been stated that, in summer, the yellow spores of a rust are -found on the under surface of birch-leaves. These must be sought on the -young twigs or suckers, proceeding from the stumps of trees which have -been cut down: pale discoloured spots on the upper surface of the leaves -indicate the presence of the rust beneath. This is the _Uredo betulina_ -of old authors (begging their pardons, for some of them still live), the -_Lecythea longicapsula_ of more recent times, and the summer spores of -_Melampsora betulina_, according to M. Tulasne and his disciples. When -fresh, it is reputed to exhale a faint odour, as of the primrose. During -the winter and spring months the wedge-like spores of the second crop -are matured on the fallen leaves (Plate IX. figs. 189, 190), and these -are capable of a speedy germination, and the production of secondary -reproductive bodies, as in the willow rust above alluded to. - -Probably, also, the similar rust on the poplar (Plate IX. figs. 195, -196), or on the aspen, may be met with under like conditions; _i.e._, -the summer spores, which are yellow and spherical, on the living leaves, -and the brown permanent masses of winter spores on the fallen and -decaying leaves. The sole remaining British species is not uncommon on -leaves of the common spurge in gardens, and whilst the yellow -pulverulent spores occur on the upper, it will not be improbable that -black permanent spots will be found on the lower leaves (Plate IX. figs. -193, 194), enclosing closely-packed, rudimentary, elongated or -wedge-shaped cellules of the winter spores. - -Any one may make himself acquainted with the genus _Coleosporium_ with -but little trouble, which the acquisition will more than compensate. A -summer stroll into any locality in which the common coltsfoot can be -found, will be certain to prove sufficient. Let the spot selected be any -station on the North Kent Railway, for those who reside in town, or even -a trip to the Crystal Palace and a stroll in the grounds, and when the -well-known leaves of the coltsfoot are descried, the under surface of -the first leaf will doubtless give proof of the presence of the fungus -in question, by the orange spores amongst its dense woolly hairs. -Sometimes the leaf is almost covered beneath with the bright -orange-coloured dust. This is the coltsfoot rust (_Coleosporium -tussilaginis_, Lev., Plate VIII. fig. 180), which may serve as a type of -the rest. It may be observed that a species of cluster-cup, or -_Æcidium_, with spores of nearly the same colour, is also to be found on -the leaves of the same plant; but in this case the upper surface of the -leaf has also corresponding purplish spots, and, what is of still more -importance, the spores are seated in small fringed cups. The rust is -common till the wintry frosts have set in, and is far more conspicuous -than the cluster-cups. A kind of di-morphism prevails in all the species -of this genus. Some of the pustules resolve themselves into a kind of -powder, whilst others remain entire and solid. Generally there is the -largest proportion of globose, dust-like, free spores, produced in the -earliest developed fungi, whilst they become more rare towards the close -of the season. The permanent spore-spots consist of obovate cellules -placed side by side, each of which is divided transversely by three or -four septa, and is filled with an orange-red endochrome (Plate VIII. -fig. 181); the exterior being enveloped in a kind of mucous layer. The -arrangement of spores when packed together in the pustule is shown in -Plate VIII. fig. 182, from an allied species. When these spores -germinate, which they do with great readiness, each division emits a -long tube, which generally remains simple and undivided, and from its -extremity is produced a reproductive body of an obovate or nearly -kidney-shape. These filaments are about 1/120th of an inch in length, of -a colourless transparent membrane, along which the orange-red contents -of the spores pass into the newly-formed sporidia, or reproductive -bodies by which they are terminated. Most of these reniform sporidia -disengage themselves from the filaments on which they are produced, and -either elongate themselves into a simple and uniform filament, or swell -at the extremity as if to reproduce a second spore. If the newly-formed -sporidia do not become free, they increase the length of their primitive -filament, which by a frequent repetition of the process becomes a tube -swelling out at unequal distances. - - -[Illustration: - - Plate X. - W. West imp. -] - - -The summer spores, or pulverulent spores of the first generation, which -are analogous to the Uredospores of _Aregma_, are also capable of -germination, for, if placed in favourable circumstances, they will -develop very long filiform processes, which either remain simple or -become more or less branched, but always nearly uniform in their -diameter. M. Tulasne states that he has observed this germination many -times, though we have been less fortunate. - -Of the six species of this genus known to occur in Great Britain, the -majority may be commonly met with. That very widely-diffused plant, the -wood cow-wheat (_Melampyrum pratense_), known well to all amateur -botanists for its pertinacity in drying black, and presenting anything -but an inviting appearance to claim for it a place in the herbarium—also -becomes the matrix for the development of a member of this genus; -_i.e._, the cow-wheat rust (_Coleosporium Rhinanthacearum_, Lev.), and -which is found on other allied plants, as the little eyebright -(_Euphrasia officinalis_), &c. (Plate VIII. fig. 176). In colour and -habit it resembles the last-named species, and its free, echinulate -spores (Plate VIII. fig. 177) form a pretty object for the microscope. - -Another equally common species is found inhabiting the leaves of the -sow-thistles (_Sonchus arvensis_ and _S. oleraceus_), and in the autumn -may generally be found on either of those plants, presenting the -appearance delineated in our plate (Plate VIII. fig. 178). The permanent -spores resemble in many points those of the first species, as will be -seen from the figure from De Bary’s treatise on this subject (Plate -VIII. fig. 179). This is certainly one of the most showy of uredinous -fungi, and could not be well overlooked. - -The butter-bur rust (_Coleosporium petasites_, Lev.) and the Campanula -rust (_Coleosporium Campanulæ_, Lev.) are found, the former on the -leaves of the butter-bur, and the latter on those of the harebell and -other _Campanulæ_, less frequently. We have, however, indicated -sufficient, since their great similarity in unprofessional eyes will -furnish, in one or two species, all that is desirable for the -microscopist. - -Unless some similar plan to the following be adopted for examining the -species of this genus, it may result in disappointment; for the slight -attachment of the joints to each other will otherwise present only a -mass of simple echinulate cellules, if a portion be only removed from -the leaf on the point of a lancet. This method consists in making a thin -vertical section of a pustule in which the spores are contained; by this -means the arrangement of the fruit and the mucedinous threads from -whence they proceed may be observed. Any person possessed of the -cardinal virtues of microscopy—patience and perseverance—will be -rewarded in this instance; whilst those who are deficient will lose an -object worthy of the virtues they dare not boast. But few instances have -occurred in this and the preceding chapters in which the exercise of any -great ingenuity or application has been called for; the most juvenile or -truest tyro at the microscope may see for himself much of what has been -indicated, whilst a few opportunities have occurred for more practised -manipulists to prove that they are neither juveniles nor tyros. - - ------------------------------------------------------------------------- - - - - - CHAPTER X. - - _WHITE RUSTS._ - - -ALLUSION has already been made to the important memoir recently -published by Dr. de Bary. “White rusts” occupy a conspicuous position in -that memoir, and the experiments therein detailed, with the conclusions -arrived at, will be largely drawn upon in furnishing the present -chapter. Whilst believing that we have fairly represented the views, and -faithfully narrated the story of research, if not literally, but denuded -of some technicality, yet in such manner as to convey the sense of our -author, we claim no originality or merit save for the garb in which it -appears, without addition, stricture, or confirmation of our own. - -What is the external appearance presented by the “white rust” of -cabbages, and allied cruciferous plants, is soon told. During summer and -autumn it occupies the surface of the leaves and stems of the -shepherd’s-purse (_Capsella bursa-pastoris_), with elongated narrow -white spots like streaks of whitewash (Plate X. fig. 198), and later in -the season the leaves of cauliflowers and cabbages become ornamented -with similar patches, arranged in a circular manner (Plate X. fig. 199), -forming spots as large as a sixpence. Wherever these spots appear, the -plant is more or less deformed, swollen, or blistered, even before the -parasite makes its appearance at the surface. These white pustules have -a vegetative system of ramifying threads which traverse the internal -portion of the plants on which they are found: these threads constitute -what is termed the _mycelium_. Not only when the plant is deformed and -swollen with its undeveloped parasite do we meet with the threads of -mycelium in its internal structure, but also in apparently healthy -portions of the plant, far removed from the evidently infected spots. -These threads are unequal in thickness, much branched, and often with -thick gelatinous walls filled with a colourless fluid. They creep -insidiously along the intercellular passages, and are provided with -certain appendages in the form of straight thread-like tubes, swollen at -their tips into globular vesicles (Plate X. fig. 204). These threads do -not exceed in length the diameter of the mycelium which bears them. The -appendages communicate in their interior with the mycelium, and contain -within them the same fluid, which at length becomes more watery, and the -terminal vesicles have their walls thickened, so as to resemble, on a -casual observation, granules of starch. Dr. de Bary conceives that these -appendages serve a similar purpose to the tendrils or suckers of -climbing phanerogamic plants; _i.e._, to fix the mycelium to the cells -which are to supply the parasite with nourishment. As these appendages -are always present, it is easy to discover the mycelium wherever it -exists amongst the tissues of an affected plant. - -The white pustules already alluded to contain the fruit of the parasite. -Bundles of clavate or club-shaped tubes are produced upon the mycelium -beneath the epidermis of the infested plant, forming a little tuft or -cushion, with each tube producing at its apex reproductive cells, -designated “conidia.” These conidia appear to be produced in the -following manner:—The tips of the clavate tubes generate them in -succession. At first a septum, or partition, divides from the lower -portion of the tube a conidium cell; this becomes constricted at the -septum and assumes a spherical shape, at length only attached by a short -narrow neck. Beneath this again the same process is repeated to form -another and another conidium in succession, until a bead-like string of -conidia surmount each of the tubes from which they are produced (Plate -X. fig. 200). At length the distended epidermis above is no longer able -to bear the pressure of the mass of engendered conidia within, and is -ruptured irregularly, so that the conidia, easily separating from each -other at the narrow neck, make their escape. - -As long since as 1807, M. Prevost described the zoospores, or moving -spores, of these conidia, and his observations were confirmed by Dr. de -Bary three years since, and are now adverted to by him again in further -confirmation. If the conidia (white spherical bodies ejected from the -pustules of the “white rust”) are sown in a drop of water on a glass -slide, being careful to immerse them entirely, they will rapidly absorb -the water and swell; soon afterwards a large and obtuse papilla, -resembling the neck of a bottle, is produced at one of the extremities. -At first vacuoles are formed in the contents of each conidium; as these -disappear, the whole protoplasm (granular substance filling the -conidium) becomes separated by very fine lines of demarcation, into from -five to eight polyhedric portions, each with a faintly coloured vacuole -in the centre. These portions are so many _zoospores_. Some minutes -after the internal division, the papilla swells and makes itself an -opening, through which the zoospores are expelled one by one, without -giving any signs of movement of their own. They take a flat disk-like or -lenticular form, and group themselves about the opening, whence they -have been expelled, in a globular mass. Soon, however, they begin to -move, vibratile ciliæ show themselves, and by means of these appendages -the entire globule oscillates, the zoospores disengage themselves from -each other, the mass is broken up, and each zoospore swims off on its -own account (Plate X. fig. 208). - -The free zoospores are of the form of a planoconvex lens, obtuse at the -edge. Beneath the plane face, out of the centre, and towards that point -of the margin which during the movement of the zoospore is foremost, is -a disk-shaped vacuole, with two ciliæ of unequal length attached to its -margin; the shorter cilia is directed forwards, and the longer in the -opposite direction, during the evolutions of the zoospores. - -The zoospores are produced within from an hour and a half to three hours -after the sowing of the conidia in water. They are never absent if the -conidia are fresh, or even a month old, but beyond this period their -artificial generation is very uncertain. This little experiment is a -very simple and interesting one, and may be performed by any one who -will take the trouble to follow out these instructions. - -From this simple experiment, let us turn for a moment to the plant in -its natural condition when affected by the white rust. If, after rain or -dew, when the little drops of moisture hang like pearls about the sickly -pallid leaves of the shepherd’s-purse, bespattered with the white -pustules of the rust, we collect and examine a drop of water from the -immediate neighbourhood of one of the pustules, we shall commonly find -empty conidia and zoospores in different stages of development. - - -[Illustration: - - Plate XI. - W. West imp. -] - - -Water alone seems to be essential to them, and for this the conidia may -remain unchanged for a month, and literally burst into activity at the -first gentle shower, till the whole surface of the plant is swarming -with zoospores. We may no longer doubt that a true vegetable produces -from itself bodies endowed with active motion, resembling low forms of -animal life, and yet in themselves not animalcules, as some would -suggest, but essentially vegetable, as we shall hereafter demonstrate. -To scientific men this is not new, except as regards fungi, for in algæ -such bodies have long been recognized. - -A second kind of reproductive organs are described by Dr. de Bary; and -if future examinations confirm his observations, as they doubtless will, -this feature is an important one. It is true that M. Caspary long since -detected similar bodies in moulds (allied to that which produces the -potato disease), but he only knew _them_ in a limited sense compared -with what De Bary has revealed. These fruits are hidden amid the tissues -of the plant on which the “white rust” is parasitic, and only betray -their presence by the coloration of those tissues. To these bodies it is -proposed to give the name of “oogonia” and “antheridia,” on account of -their presumed sexuality, the “oogonia” representing the female, and the -“antheridia” the male organs. - -The oogonia are large spherical or ovoid cells, with a thickish membrane -containing a granular protoplasm, or formative fluid. They are produced -either terminally or laterally upon the threads of the mycelium, from -which they are separated by septa or partitions. - -The antheridia are somewhat blunt-shaped or obovate cellules, -considerably smaller than the oogonia, with slightly thickened walls, -and containing a finely granular protoplasm. These are produced upon -branches of the mycelium which do not bear oogonia. The obtuse -extremities of these branches, which are to be developed as antheridia, -are applied to the surface of the growing oogonia, to which they adhere, -become distended, assume their obovate form, and by the formation of a -septum at their base, their contents are isolated from those of the -threads of the mycelium, and thus the antheridia are perfected. - -When these bodies have attained their full dimensions, the large -granules which are contained in the oogonium accumulate at its centre, -and form an irregular, somewhat spherical mass, which is called by De -Bary a _gonosphere_. This gonosphere having been formed, a straight tube -shoots out from the antheridium which perforates the wall of the -oogonium, passes through the fluid which surrounds the gonosphere, -elongating itself until it touches that body. From this period a -membrane begins to be formed about the gonosphere, which thenceforth -maintains a regular spheroidal form. It may be observed that the -extremity of the tube which proceeds from the antheridium does not open, -and the fecundation, if such it be, is produced solely by contact. After -this contact of the two bodies, the gonosphere acquires a new name, and -is called an “oospore.” The membrane which at first invests this organ -is very thin, but by deposits from the surrounding fluid it attains to a -greater thickness, and is at length of a yellowish-brown colour, having -its surface studded with large obtuse warts (Plate X. fig. 206). One of -these warts, larger than the rest, forms a kind of thick sheath around -the fecundating tube. - -The oospores do not give evidence of any appreciable change for some -months. For instance, those collected by De Bary in June did not attain -their ulterior development until the commencement of December. The -method adopted was as follows:—Parts of the plants containing ripe -oospores were preserved in the dried state. When examination was -considered desirable, the portion to be employed was immersed in water -for a day or two; it was then placed on a humid soil, or mould covered -with blotting-paper. The tissues enclosing the oospores were decomposed, -and at the end of from four to eight days their germination might be -observed when placed in a drop of water. This method again corresponds -with the ordinary processes by which the plant naturally decays on -exposure to the influences of the atmosphere, and the oospores germinate -under the favour of a shower of rain. - -If the oospore, after the decay of the tissues, is isolated and placed -in a drop of water, the brown investing membrane will be seen to rupture -irregularly, and its contents (enclosed in a transparent inner membrane) -issuing from the orifice. As in the case of the conidia, this body at -first contains vacuoles, and is afterwards divided into polyhedric -portions; these pass into zoospores, which congregate at the centre into -a globular mass (Plate X. fig. 207). They afterwards separate, and for -some minutes float about in the vesicle in which they were generated. -Ultimately the membrane ruptures, and the zoospores swim about in water -just as those produced from the conidia had done. The number contained -in each oospore is considerable, and may be estimated at not less than -one hundred. - -The zoospores, whether produced from conidia or from oospores, appear to -be the same. The movements of both in the water last from two to three -hours; then they cease, the ciliæ disappear, and the zoospores remain at -rest, taking meanwhile a globular form. Afterwards these spores (for -having ceased all motion they are no longer zoospores) emit a thin tube -from some portion of their surface, such tube attaining a length of from -two to ten times that of the spore whence it proceeds. The extremity of -these tubes swells and forms a kind of cell, into which the contents of -the spore pass through the medium of the tube (Plate X. fig. 209). - -Thus far, and thus far only, has Dr. de Bary been enabled to trace the -development of the zoospores in a drop of water. Another series of -experiments was instituted by this mycologist having especial reference -to the parasitism of the “white rust.” He made numerous observations to -ascertain whether the spores, or the germinating tubes, entered by the -roots of growing plants, and satisfied himself that they did not. Plants -of garden-cress, mustard, and shepherd’s-purse had their roots immersed -in water impregnated with zoospores. After one or two days, though the -surfaces of the roots were covered with zoospores that had emitted their -germinating tubes in all directions, none had penetrated or showed the -least tendency to penetrate the epidermis. Other plants were planted in -flowerpots and watered at the roots with water charged with zoospores, -and for two days the pots were left standing in the water similarly -charged, then the plants were removed, cultivated in the ordinary -manner, grew up healthy, and gave no signs of the white rust. Care had -been taken that neither stems nor leaves should come in contact with -water containing zoospores. - -If a drop of water thus charged is placed on the surface of a living -leaf of the shepherd’s-purse, for instance, and left at rest for a few -hours and examined minutely at the end of that period, they will be -found to have germinated. Let the epidermis be removed carefully and -placed on a glass slide and submitted to the microscope. Many zoospores -will be found to have produced from that point of their surface which is -nearest to one of the stomata, or pores of the leaf, its slender tube, -and to have thrust it through those openings, with the swollen extremity -resting in the air-cavity situated beneath the pore. If many days, or -even weeks, are allowed to pass, and the leaf is examined again, or -another leaf similarly treated, and kept in a living and vigorous -condition by remaining attached to the parent plant, still no further -change or advance will be observed, the germs will appear fresh, and -still in the same condition. Hence it is concluded that plants are not -infected through the medium of their leaves. - -If the cotyledons, or seed-leaves, are watered with similar impregnated -water, a different result has been observed to take place. The -germination of the tubes till their entrance at the stomata is the same; -but, having entered, the swollen extremity elongates, becomes branched, -and takes all the appearance of mycelium such as we at first described. -If the infected plant endures through the winter, the mycelium endures -with it, to recommence vegetating in the spring. - -The experiments which Dr. de Bary performed were all upon plants of the -common garden-cress. It will be unnecessary to repeat all the details of -these, as given in the memoir recently published on the subject, but it -will suffice to give a summary of results. In two series of plants -cultivated at different periods from good seeds, one hundred and five -plants which, had not received the water impregnated with zoospores upon -their cotyledons vegetated without any indications of the parasite. -Amongst the eighteen plants which were inoculated by watering the -cotyledons, four only were not attacked by the parasite, fourteen bore -the “white rust.” In six of these it did not extend beyond the -cotyledons; in the others it also appeared on the stems and leaves. - -From these experiments it may be deduced that plants are not infected by -spores of the parasite entering at the roots, or by their leaves, but -that inoculation takes place through the medium of the cotyledons, or -seed-leaves; that the agents in this inoculation are the zoospores -produced either from the conidia or the oospores; that they do not enter -the stomata or pores themselves, but thrust out a germinating tube, into -the extremity of which the contents of the zoospores pass; that when -these tubes have entered the stomata of the cotyledons they branch and -ramify, becoming a true mycelium, from which fruitful parasites are -developed; that if a plant so infested lives through the winter, the -parasite lives with it, to vegetate again in the spring. - -The immense number of zoospores capable of being produced from a single -infested plant is almost beyond calculation. It is easy for a million of -conidia to be developed from such a plant, each producing from five to -eight zoospores, besides a large number of oospores, each containing a -hundred zoospores. It can scarcely be considered marvellous that the -white rust should be so common on plants favourable to its development, -the marvel being rather that any plant should escape. - - -[Illustration: - - Plate XII. - W. West imp. -] - - -Until recently it was doubtful whether more than one or two species of -_Cystopus_ (white rust) were known. It is now certain that we have three -in Great Britain, and three or four others are found elsewhere. Of the -British species one is found on many cruciferous plants, as the -shepherd’s-purse, garden-cress, mustard, radish, and plants of the -cabbage kind. This is the _Cystopus candidus_. Another occurs on the -goat’s-beard, salsify, and scorzonera, which is called _Cystopus -cubicus_. Both have great external resemblances, but both possess -specific internal differences. In the Goat’s-beard rust (Plate X. fig. -201) the terminal conidia in the bunches or fascicles of conidia which -are produced within the pustules are spheroidal, large, and of a -yellow-brown tint, whilst the residue are cylindrical, smaller (Plate X. -fig. 202), and more or less compressed. In the crucifer rust the conidia -are all equal in the pustules and globose. The oospores in the former of -these are subglobose and the warts on their surface are solid; whilst in -the latter the oospores are truly globose, and the warts on the surface -are hollow (Plate X. fig. 210). The third species is the Sandspurry -white rust (_Cystopus Lepigoni_), which was found on the common -sandspurry (_Spergularia rubra_) by Mr. R. G. Keeley, in Swanscombe -Marshes (September, 1864). Of the other species it is not improbable -that one or two may yet be found in this country. Without attempting to -indicate their microscopic differences, it may be serviceable to name -the species of phanerogamic plants on which they are likely to be found. -The Purslane white rust (_Cystopus Portulacæ_, D. C.) should be sought -on the purslane, which, though of limited cultivation, is exceedingly -liable to attack from this parasite, and the Thistle white rust -(_Cystopus spinulosus_, D. By.) may probably be met with on the leaves -of the common thistle (_Cnicus arvensis_) or some of its allies. - -Considerable interest is now attached to these parasites, which, as far -as we at present know, differ materially in their reproduction from the -other dust-like or uredinous fungi with which they have long been -associated. Dr. de Bary proposes the union of these with the mould-like -fungi of the genus _Peronospora_, to which the mould infesting the -potato belongs, so as to constitute by themselves a group apart from the -genera with which both have heretofore been associated. Whether his -views will be accepted by mycologists time will speedily prove. Under -any circumstances, microscopical and botanical science will reap -considerable benefit from his researches. - - ------------------------------------------------------------------------- - - - - - CHAPTER XI. - - _MOULDS._ - - -TWENTY years since, and some of these little pests were altogether -unknown, whilst others were only recognized and partly understood by a -few scientific men. During the period to which we have alluded more than -half the present species contained in the genus _Peronospora_ had never -been observed, and amongst these the most devastating of its tribe, the -associate and undoubted cause of the potato disease. - -Parasitic fungi are far more numerous, both in individuals and species, -than most persons are aware, and cultivated plants of all kinds are more -or less subject to their ravages. Some are more susceptible than others, -of which the corn and grass tribe, or _Graminaceæ_, as they are termed -by botanists, is an example. Not less than thirty species have been -recorded upon plants of this natural order, and of these nearly one-half -are found upon the living plants. Upon the potato plant, again, no less -than ten different kinds of fungi have been described; whilst upon other -and more fortunate plants only one or two parasites of this nature -establish themselves. - - - Plate XIII. - -[Illustration: - - 262.—TURNIP MOULD. - _Peronospora parasitica._ -] - -[Illustration: - - 263.—ONION MOULD. - _Peronospora Schleideniana._ -] - - -It will be sufficient for our present purpose to state that one of the -six families into which fungi are divided for scientific purposes is -called _Hyphomycetes_, a name compounded of two Greek words signifying -“thread” and “mould,” or “fungus,” and is applied to this group because -the thread-like filaments of which they are largely composed are the -most prominent feature. In this family there are again a number of -smaller groups called orders, having an equal value to the natural -orders of flowering plants; and one of these orders, called _Mucedines_, -has the fertile threads perfectly distinct from the mycelium or spawn. -These threads are sometimes simple and sometimes branched; they may be -articulated or without articulations or septa, short or long, erect or -creeping, hyaline or whitish, mostly free from colour, and are not -coated with a distinct membrane. The spores are generally simple, -sometimes solitary, at others in pairs, or strung together like beads -for a necklace. Amongst all this variety of arrangement there is order, -for these are but features, or partly the features, of the different -genera of which the _Mucedines_ are composed. One of the genera is -termed _Peronospora_, and to this the parasitic fungus of the potato, -and some others to which we shall have occasion to refer, belong. In -this genus the threads are generally branched, but without -articulations. The spores, or seed-like bodies, are of two kinds; one -kind is borne on the tips of the branches; and the other kind, which is -larger and globose, is borne upon the creeping mycelium or spawn. All -the members of this genus with which we are acquainted are parasitic on -living plants, inducing in them speedy decay, but preceding that decay -of which they are themselves the cause. Hence we have deemed it the more -advantageous course both for writer and reader to associate together the -different species of this particular genus of parasitic moulds in one -chapter, rather than bring together the different kinds of fungi, -belonging perhaps to widely separated genera, but all associated with, -or parasitic upon, the same plant. The botanical student will thank us -for following this plan, and the general reader will labour under no -disadvantage, in this instance at least, from the similarity of the -diseases produced in the plants infested. - -It has been recently proposed to associate the genera _Peronospora_ and -_Cystopus_ together in one group, under the name of _Peronosporei_; but -with the discussion of this subject we have nothing to do in this -volume. Having announced this fact, we shall continue to notice them in -the several positions heretofore accorded to them. - -The mycelium (root-like fibres) in this genus greatly resembles that -described for the “white rusts,” though neither so thick, nor is the -membrane so gelatinous as in that genus. In some instances the mycelium -is confined to the inter-cellulary passages; but in most cases they also -perforate the cells of the plant which nourishes them. The sucker-like -bodies already described in _Cystopus_ are often found produced on the -mycelium of _Peronospora_, but occasionally they appear to be absent, -especially in the mould causing the potato disease. - -From the mycelium erect threads are produced, upon which one form of -fruit, which may be termed “acrospores,” is borne. These filaments are -sometimes single, and sometimes in small tufts or fascicles. In some -instances they are considerably branched, so as to present a dendroidal -or tree-like appearance; in others they are nearly simple, being only -surmounted by short spicules; or, in one instance, quite simple, and -only surmounted by a single acrospore. The branching habit is by far the -most common. - -Each ultimate branch in the ramification of the fertile filaments -engenders a single acrospore. Its extremity, at first thin and pointed, -swells in the form of a globular vesicle, which soon takes the -elliptical or ovate shape of the perfected acrospore, and at length -separates itself from the branch that supports it. - -In all instances the acrospores have a similar structure, but with -minute differences in form, &c., which have their importance in the -determination of species. In most cases the apex of the acrospore is -obtuse, and the entire body has a violet tint, more or less deep; in -some it is completely colourless. These acrospores, when placed in -favourable conditions, will germinate, and, in fact, comport themselves -in the manner of true spores. - -During the year 1861, Dr. de Bary published an account[8] of the -discovery by him of zoospores, similar to those already described in -connection with the conidia of the “white rusts,” produced from the -acrospores of the mould which originates the potato disease. In the same -author’s memoir of 1864, already quoted, the observations there made are -confirmed. When the acrospores of the potato mould and the parsnip mould -are sown in water upon a glass slide, their contents become divided, and -vacuoles are formed, as already described in _Cystopus_; these parts are -expelled through an apical orifice, and, when free, take the form of -perfect zoospores, and commence swimming about in the fluid surrounding -them. - -Footnote 8: - - Die gegenwartig herrschende Kartoffelkrankheit, ihre Ursache und ihre - Verhütung. Von Dr. A. de Bary. Leipsig: 1861. - -These zoospores are oval, or semi-oval, with a structure resembling that -of the “white rusts,” save that the two ciliæ, or vibratile hairs, -proceed from the same point. The number of zoospores from each acrospore -of the potato mould is stated to be from six to sixteen, and in the -parsnip mould from six to fourteen. Their ultimate development is the -same as has already been described. In the potato mould, the production -of the zoospores is much favoured by the exclusion of light. - -Another mode of germination in the acrospores of the potato mould has -been observed by the same eminent mycologist. This results when the -spores are sown upon a humid body, or on the _surface_ of a drop of -water. The acrospore emits from its summit a simple tube, the extremity -of which swells into an oval vesicle; into this the contents pass, and -it isolates itself by a partition from the germ-tube. Thus it becomes a -duplicate of the acrospore from whence it was derived. This secondary -body has also the power of producing a tertiary cellule in a similar -manner. Both the second and third cellule, when _immersed_ in water, -produce zoospores in the ordinary manner, as above described. - -Yet another and a third mode of germination is described by the same -author, in which the acrospore emits from its apex a germ-tube, which -elongates considerably; and into this long and tortuous tube the -contents of the acrospore pass, and accumulate at the opposite -extremity. - -The germ-tubes, produced in the manner last described, when developed on -the surface of a favourable plant, perforate the cells of the epidermis, -or enter by the stomata. In the case of the potato mould, the germ-tubes -enter by the stomata; but in the majority of species the germ-tubes do -not enter by the natural pores of the leaves upon which the acrospores -are sown, but perforate the cellules, and thus effect admission into the -tissues of the plant, where they extend, ramify themselves, and become a -mycelium. This mycelium originates branched threads, bearing acrospores -at the tips of their branchlets, and in many species of _Peronospora_ -another kind of reproductive body upon the threads of the mycelium -itself. To these bodies we must briefly address ourselves. - -This last kind of reproductive organs (not yet positively found in the -potato mould) appear to be wholly analogous to the oogonia of the “white -rusts” already described, producing oospores in like manner. Dr. de Bary -avows with regret that his numerous efforts to observe the germination -of these oospores were unsuccessful. Nevertheless, he considers that the -perfect resemblance between them and the oospores of the “white rusts” -will justify him in concluding that the germination in both is very -similar. It will be unnecessary to repeat here the observations already -made on the growth and development of oogones and zoospores. What has -been advanced respecting these organs in _Cystopus_ will apply also to -_Peronospora_. - - - Plate XIV. - -[Illustration: - - 264.—POTATO MOULD. - _Peronospora infestans._ -] - -[Illustration: - - 265.—LETTUCE MOULD. - _Peronospora gangliformis._ -] - - -POTATO MOULD.—Towards the close of the summer of 1845, in the course of -a few weeks, every one became aware of the fact that a new disease had -appeared which threatened the entire destruction of the potato crop. -Until then it seemed to have been almost, although not entirely unknown. -It first appeared in the Isle of Wight about the middle of August, and a -week afterwards had become general in the South of England, and the next -week there were but few sound samples of potatoes in the London market. -Early in September the disease had commenced its ravages in Ireland, and -shortly afterwards it was discovered in Scotland. With the same rapidity -it seems to have spread throughout Europe and North America, or at least -the western portion of the former and the northern districts of the -latter. It must not be imagined, however, that the Isle of Wight was the -centre from which this disease spread over such an extended area and -with such alarming rapidity. From this spot it doubtless made its first -appearance that year amongst our own crops, but there is not the least -doubt of its existence both on the continent of Europe and in North -America in the previous year, and the farmers of Belgium had noted its -appearance in the province of Liège as far back as 1842 and 1843. Other -diseases had been observed affecting the potato crop before, and one -which was also associated with a parasitic fungus had made its -appearance in 1815. It is also exceedingly probable that, in a milder -form, the murrain was present with us a year or two before it broke out -to such an alarming extent. A correspondent to the _Gardeners’ -Chronicle_, in 1844, notices it in the Isle of Thanet, and another -testifies to its occurrence in districts of Ireland for two or three -years previous to its general outbreak. The description of the disease -in Canada, in 1844, contained in a letter addressed to Dr. Bellingham, -and quoted by the Rev. M. J. Berkeley,[9] leaves no doubt of its -identity:—“During the months of July and August (1844), we had repeated -and heavy showers, with oppressive heat, and an atmosphere strongly -charged with electricity. Towards the close of the month of August I -observed the leaves to be marked with black spots, as if ink had been -sprinkled over them. They began to wither, emitting a peculiar, -offensive odour; and before a fortnight the field, which had been -singularly luxuriant, and almost rank, became arid and dried up, as if -by a severe frost. I had the potatoes dug out during the month of -September, when about two-thirds were either positively rotten, -partially decayed and swarming with worms, or spotted with -brownish-coloured patches, resembling flesh that had been frost-bitten. -These parts were soft to the touch, and upon the decayed potatoes I -observed a whitish substance like mould.” - -Footnote 9: - - Journal of Horticultural Society of London, vol. i. p. 11. - -Although this disease made its first appearance, in the middle of -August, 1845, in the Isle of Wight, it had already appeared in Belgium -in the same year, a month previously; and although it may have been -noticed in other British localities in 1844, it was known in Canada and -in St. Helena in the same year to a far greater extent, and in Liège as -early as 1842. There are, therefore, good grounds for believing that the -European centre was Belgium; but if M. Boussingault was correct in -stating that “this malady is well known in rainy years at Bogota, where -the Indians live almost entirely on potatoes,” then it is not of -European but American origin, and is probably derived from districts not -far remote from those whence Europe first received the potato itself. - -It would occupy too much space to detail the different theories and -opinions relative to the causes of this disease to which 1845 and -subsequent years gave birth. Suffice it to say, that the lapse of years -has silently proved the majority of these to have been fallacious. All -such as imputed to peculiar electric conditions, a wet season, or other -meteorological influences, the disease which has re-appeared under -different conditions and influences, and in seasons remarkable for -dryness, are manifestly refuted; whilst its mycological origin has -continued to gain adherents, and the gradual accumulation of fresh facts -has almost placed it beyond dispute not only that the potato disease is -accompanied by, but results from, fungal growth. Unfortunately, this -disease has been so prevalent, more or less, during the past eighteen -years, that few have been without the opportunity of making themselves -acquainted with its external appearance. To this may be added the minute -and exact account of its development, as recorded by that excellent -mycologist and careful observer, the Rev. M. J. Berkeley, in 1846, and -to which, even now, nothing of importance can be supplemented or -abstracted:—“The leaves began suddenly to assume a paler, and at length -a yellowish tint, exhibiting here and there discoloured spots. More or -less coinciding with these spots, on the reverse of the leaves, appeared -white mealy patches, consisting of a minute mould, proceeding, either -singly or in fascicles, from the stomata, and arising from an abundant -branched mycelium creeping in every direction through the loose tissue -beneath the cuticle. The upper surface rarely, if ever, exhibits the -mould, it being almost physically impossible for its delicate threads to -penetrate the closely-packed cells which, being arranged side by side, -leave scarcely any intercellular passages. The mould, in a few hours -from its first piercing the apertures of the stomata, perfects its -fruit, and in so doing completely exhausts the matrix, which in -consequence withers. No sooner have a number of the leaves been -attacked, than the stem itself is subject to change, becoming spotted -here and there with dark brown patches, in which the cells are mostly -filled with a dark grumous mass, without exhibiting any mucedinous -filaments; though, occasionally, I have ascertained their presence. Very -rarely fructifying but dwarfed specimens of the mould occur upon it. The -stem now rapidly putrefies, the cuticle and its subjacent tissue become -pulpy, and separate when touched from the woody parts beneath. The whole -soon dries up, and in many instances exhibits in the centre the black, -irregular fungoid masses which are known under the name of _Sclerotium -varium_, and which are believed to be the mycelium of certain moulds in -a high state of condensation. - -“If the tubers are now examined, the greater part will often be found -smaller than usual, especially if the disease has commenced at an early -stage of growth; but in their natural condition, while here and there a -tuber, particularly if it has been partially exposed, exhibits traces of -disease. The surface is, however, soon marked with livid patches, -commencing generally about the eyes, or at the point of connection with -the fructifying shoots: these rapidly acquire a spotted appearance, the -spots being rather waved, and assuming often a more or less concentric -arrangement. Sometimes—especially on the smoother kinds of tuber—two or -more regular systems of concentric spots are exhibited on the same -tuber. The skin now withers, and is easily separated; the spots become -depressed and of a yellowish tinge; and if the tubers be laid in a moist -place, in a day or two—sometimes in a few hours—the same mould which -destroyed the leaves springs from them, piercing the cuticle from -within, yet not scattered, as on the leaves, but forming a conspicuous -white tuft. If a section of the diseased tuber be made on the first -symptoms of the disease, little brownish or rusty specks are found in -the cellular tissue, confined, with very rare exceptions, to the space -between the cuticle and the sac, if I may so call it, of spiral vessels -and their accompanying tissue, which, springing from the subterranean -branches, pass into the tuber, making their way to the several buds -disposed on the surface. These spots consist at first of a quantity of -discoloured cells, mixed more or less with others in a healthy -condition. The grains of fecula are for a long time perfectly healthy; -the cells themselves, so far from being looser, are more closely bound -together than in the more healthy portions. The rusty spots soon exhibit -a darker tint, spreading in every direction and becoming confluent; they -at length extend beyond the barrier of vascular tissue, and attack the -central mass. The tuber, meanwhile, assumes a disagreeable smell, -decomposes more or less rapidly, other Fungi establish themselves on the -surface, or in the decaying mass, which emits a highly fetid odour, -resembling that of decaying agarics; the union of the cells is -dissolved, animalcules or mites make their appearance, till at last the -whole becomes a loathsome mass of putrescence.” - -The form of the mould itself is represented (fig. 264) as exhibited -under the microscope, with the nodose swellings of the branches, and -spores attached to the tips. These acrospores are filled with a granular -mass, from which, as hereafter described, zoospores are produced. The -branching dendroidal threads of this fungus proceed from a creeping -mycelium or spawn of entangled filaments which interpenetrates the -matrix, upon which it establishes itself. Upon these threads spherical -bodies were long since observed by Dr. Payen, and, under the name of -_Artotrogus_, described by Dr. Montagne as a new species of fungus. Dr. -de Bary failed to detect oospores on the mycelium of this mould, -although the organs found by Payen in some sort resemble them. De Bary -sought in vain, also, for the spherical bodies described by the author -above named. It has been calculated that one square line of the under -surface of the leaves is capable of producing 3,270 acrospores, each of -which yields at least six zoospores, sometimes double that number; thus -we have 19,620 reproductive bodies from that small space. The mycelium -from the zoospores is capable of penetrating the cellular tissue in -twelve hours, and, when established there, it bursts through the stomata -of the leaves, and fruit is perfected in from fifteen to eighteen hours. -Since the zoospores are perfected and ready to germinate in twenty-four -hours from their being placed in water, it becomes almost impossible to -calculate the myriads of fungi that may be produced from a single -centre. Dr. de Bary has also demonstrated that the brown spots so -characteristic of the disease are the result of the action of the spores -or zoospores. By placing a quantity of spores in a drop of water on the -leaves, stems, and tubers under a glass sufficiently air-tight to -prevent evaporation, he produced the brown spots, and traced their -progress from the earliest stages. - -There are a few practical conclusions which may be drawn from these -discoveries. In the first place, it is clearly shown by the production -of the spots that the fungus is capable of _causing_ the disease, a fact -which has been disputed, but now placed beyond doubt. The inference is, -that not only is it capable of producing, but is really the cause of the -potato murrain. With bodies so minute and active as the zoospores, there -can no longer be difficulty in accounting for their penetrating the -tissues of the plant. They are most active and productive in wet -weather, especially when it is also warm. Moisture appears to be -essential, and a dry season the greatest enemy to the spread of the -disease. That bodies so minute and subtle should have baffled all -efforts to destroy or eradicate, is not now surprising. Whether any -method will be found to contend successfully with it, is now more -doubtful than ever. A careful reperusal of the old facts by the aid of -this new light will tend to the elucidation of much of the mystery in -which the subject has been involved. All who have hitherto been -sceptical of the mycological source of one of the greatest pests of -modern times should study M. de Bary’s pamphlet. - - - Plate XV. - -[Illustration: - - 266.—PEA MOULD. - _Peronospora Viciæ._ -] - -[Illustration: - - 267.—ANEMONE MOULD. - _Peronospora pygmæa._ -] - - -The potato mould has been judiciously named _Peronospora infestans_, or, -as it was at first called, _Botrytis infestans_; but on a revision of -the genera _Botrytis_ and _Peronospora_, it was transferred to the -latter genus, in which it remains. Three names were given to it, within -a short period of each other, by different mycologists, in ignorance of -its having already received a name. The one we have adopted appears to -have the priority, at least of publication, and was given by Dr. -Montagne. That of _Botrytis devastatrix_ was given by Madame Libert, and -_Botrytis fallax_ by M. Desmazières. The principal feature in this -species seems to consist in the branches becoming alternately thickened -and constricted, so as to resemble a moniliform string or necklace of -little bladders or vesicles. The branches are also more erect than in -the allied species, and the spores are solitary on the tips or from the -sides of the branches, and not in pairs or clusters, and the tips are -simple, and not bifid or trifid, as in most of its allies. It need -scarcely be remarked, that a high power of the microscope is necessary -to make out the distinctive features of the different members of this -genus, and that to the naked eye they only appear as a minute whitish -mould. As already stated, this little fungus makes its first appearance -on the under surface of the leaves, especially the lower ones, of the -potato plant, and afterwards attacks the stem, and ultimately the tuber. -For examination it is better to select the leaves soon after the fungus -makes its appearance. - -TURNIP MOULD.—Since the advent of the potato murrain a similar disease -has been witnessed, though more limited in its extent, amongst Swedish -turnips, commencing in little waved irregular lines following the course -of the vessels, around which spots are formed by the deposition of dark -granules in the same manner as in the potato. In this instance, the -leaves apparently are first attacked in a similar manner by a species of -mould or _Peronospora_ allied to the one already described, but which -has been long known as parasitic upon cruciferous plants, to which the -turnip belongs. This species, termed _Peronospora parasitica_, is white -in all stages of its growth. It is much more branched, and the branches -are comparatively shorter than in the potato mould, and the tips of the -branches are bifid (fig. 262). The acrospores are very large and -globose, features also which distinguish this mould from the last. A -short time since we were called to witness a bed of splendid -cauliflowers, which had, up to that time, been the pride of their -cultivator; but, alas! their glory was threatened with speedy -annihilation, for in nearly every instance the lower leaves had become -more or less covered on their upper surface with yellow spots, and -beneath glaucous with the mould we have been describing. The diseased -leaves were all immediately removed, but we fear without success, -although no positive information has since reached us. The almost -unnatural vigorous green of the leaves, prior to the appearance of the -mould, is not at all an uncommon occurrence: this phenomenon has been -noticed in the ears of corn, in which every grain was soon afterwards -filled with spores of bunt. - -This species was at one time believed to be parasitic on the “white -rust,” from which circumstance its specific name was derived. More -precise examination proves that it sometimes occurs where no white rust -is present, and therefore its parasitism is imaginary. The suckers in -this species are large and penetrate the cells, often entirely filling -them. This feature is sufficient to distinguish the mycelium of the -mould from that of the “rust.” The turnip mould occurs on many -cruciferous plants, and especially on the shepherd’s-purse, as well as -upon the different varieties of cabbage and its more immediate allies. - -ONION MOULD.—Another disease, produced by fungi of the same genus, makes -its appearance upon young onion plants in the spring. The mould is -called _Peronospora Schleideniana_, and has many features in common with -those already described. In this instance the threads are greyish and -erect, with alternate branches, not divided by transverse septa, and the -spores are obovate, attenuated towards their base (fig. 263). This -mould, in some years, is very common and destructive, by preventing the -young plants which are attacked from coming to perfection. It is not -confined to the onion, but appears on other allied species of _Allium_ -(to which the onion belongs). The threads form large patches or blotches -on the leaves, and sometimes cover them entirely. It very much resembles -the turnip mould, from which the form of the spores considerably -differs. This is the same species as that described by Caspary, and -afterwards by Berkeley, under the name of _P. destructor_. - -_Lettuce Mould._—A very similar mould (_Peronospora gangliformis_) is -sometimes very common in spring on the under surface of the leaves of -the cultivated lettuce, appearing in definite white mouldy spots. By -reference to the figure of a portion of a thread magnified (fig. 265), -it will be seen that the peculiar form of the tips of the branchlets -evidences the distinctness of this species. - -The oospores are small, globose, and of a yellowish-tawny colour. This -mould is by no means confined to lettuces, but has also been found on -species of ragwort, sow-thistle, nipplewort, endive, and other composite -plants; and has from time to time received numerous names, which it is -unnecessary to enumerate. - -TARE MOULD.—The under surface of the leaves of tares, and sometimes also -of peas, is liable to attack from an allied species of mould -(_Peronospora Viciæ_). In the spring of 1846 it appeared amongst vetches -in some districts to such an extent as at one time to threaten the -destruction of the crops; but a succession of dry weather at once -abridged its power and limited its mischief. Mouldy vetches and mouldy -peas are, especially in moist seasons, evils to which the agriculturist -knows his crops to be subject; he may not know, however, that this kind -of mould (fig. 266) is of so near a kin to that which has acquired such -wide-spread fame in connection with the potato. Another species of -fungus attacks the garden pea in damp seasons, forming small depressed -brownish spots on the leaves and pods; but this is quite distinct from -the mould, though probably not less injurious. - -The fertile threads are produced in dense clusters, each many times -branched, and bearing elliptic acrospores obtuse at their apices, and of -a violaceous tint (fig. 266). The oospores are beautifully reticulated -and of a yellowish-brown colour (Plate X. fig. 212). - -Trefoil and some other allied plants are attacked by another species, -characterized by Dr. de Bary as _Peronospora trifoliorum_, which we have -found rather plentifully in some localities on lucern. - -THE PARSNIP MOULD (_Peronospora nivea_, Ung.) is found on many -umbelliferous plants; but its attacks upon the parsnip are most to be -deplored, because it injures and ultimately destroys an article of human -food. The plants infested with this parasite are first attacked in the -leaves, but afterwards the roots become spotted and diseased in a -similar manner to the potatoes attacked by its congener. The disease has -not hitherto been so general with the former as the latter; but in some -districts it has been far from uncommon. - -The fertile threads are collected in bundles, erect, and not so much -branched as in many other species. The acrospores are subglobose or -ovoid, and papillate at their apices. This species is sometimes called -_P. umbelliferarum_, and sometimes _P. macrospora_. Generally speaking -the average humidity of a season but little affects the production of -parasitic fungi. In a dry season, like that of 1864, we found as many -species, and these as flourishing and numerous in individuals, as in a -proverbially wet year. Such is not the case, however, with the moulds -under notice, or such fungi as are reproduced through the medium of -zoospores: these are undoubtedly less common in a very dry season; but -it must be remembered that a single shower is sufficient for the -development of zoospores, and occasional showers or heavy dews will -speed them on their course of destruction as readily almost as -continuous moisture. The large fungi, on the contrary, become very -limited in numbers when the weather is unusually dry. - -SPINACH MOULD.—Spinach is likewise liable to suffer from the -establishment of a mould upon the under surface of the leaves: -unfortunately this is not unfrequent, and has been known in England -certainly for the last fifty or sixty years, since it was figured by -Sowerby in his “British Fungi” as many years since. We have lately seen -a bed of spinach, utterly destroyed by this fungus; whilst on another, -not twenty yards apart, not a spotted leaf could be found. This mould is -the _Peronospora effusa_ of botanists; it occurs also on some species of -goosefoot (Plate X. fig. 215), and probably on knotgrass. To the naked -eye it appears in pale purplish-grey patches, which, when examined -microscopically, are found to consist of dense bundles of branched -threads, bearing ellipsoid acrospores, the membranes of which have a -violaceous tint. The oogonia produced upon the mycelium vary -considerably in size. The oospores are of the character delineated in -our plate (Plate X. fig. 214). - -Hitherto all the species of mould to which we have had occasion to refer -have been found infesting plants more or less employed as food; but -there remain one or two other species to which we must make special -reference. One of these affects the most universal of favourites amongst -flowers: this is the rose mould. Attention was directed to this mould, -and it was described for the first time under the name of _Peronospora -sparsa_, in the columns of the _Gardeners’ Chronicle_, in 1862. It -occurred on a quantity of potted rose-plants in a conservatory. -Irregular pale brownish discoloured spots appeared on the upper surface -of the leaves; these extended rapidly, and in a short time the leaves -withered and shrivelled up, and ultimately the whole plant perished. A -delicate greyish mould was to be seen by the aid of a lens, scattered -over the under surface of the leaves. By the microscope, the branched -threads, having the tips furnished with subelliptic spores, were -revealed, and an ally of the potato mould found revelling amongst the -roses. - -During the winter of 1863-4, we found the leaves of several species of -dock occupied by a mould which appears to be a very low form of -_Peronospora_. Its presence was indicated by brownish orbicular spots, -on which the fertile threads occurred in small bundles. These threads -were generally simple, but occasionally forked, bearing rather large -elliptical acrospores _attached obliquely_ to the tips of the threads -(fig. 269). In consequence of this peculiarity, we have named the -species, which does not appear to have been noticed before, _Peronospora -obliqua_. It is clearly very distinct from another species found on dock -leaves by Corda. - -Of the remaining British species, one (_P. Arenariæ_) is found on the -leaves of the three-veined sandwort (fig. 268); another attacks the red -corn-poppy, a third is found on the common nettle, one on the brooklime, -another on the wood-anemone (fig. 267), and another on the figwort. - -Doubtless all the species in this genus are possessed of the third means -of reproduction, by zoospores, as discovered in the potato mould, not -only from the acrospores, but also from the oospores. - - - Plate XVI. - -[Illustration: - - 268.—SANDWORT MOULD. - _Peronospora Arenariæ._ -] - -[Illustration: - - 269.—DOCK MOULD. - _Peronospora obliqua._ -] - - -The fearful rapidity with which this method enables them to multiply -themselves may account for their widely spreading and devastating power. -No other genus of fungi can parallel this in the number of species -injurious to the field or the garden, or in which the injuries inflicted -are so great and irremediable. - - * * * * * - -N.B.—Since the foregoing chapter was in type, the Rev. M. J. Berkeley -informs us that both Mr. Broome and himself have examined the mould on -dock-leaves, to which we have given the name of _Peronospora obliqua_, -and have come to the conclusion that it is truly a member of that genus, -and not hitherto described; but they are also of opinion that it is the -same mould as one described by Dr. Montagne as _Ascomyces Rumicis_. We -concur with them in thinking it deficient in the important -characteristics of _Ascomyces_, and therefore retain its proposed name -of _P. obliqua_. - - ------------------------------------------------------------------------- - - - - - CHAPTER XII. - - _WHITE MILDEWS OR BLIGHTS._ - - -NOTWITHSTANDING the inconvenience to ourselves of calling very different -fungi by the same common name of “mildew,” the popular mind does not -recognize the inconvenience, since it scarcely troubles itself to -inquire whether they are not all the same thing. In obedience to this -custom, we again write of “mildew,” or “blight,” as it is called in some -districts, but of a very different kind to that which is so detrimental -to growing crops of corn. In the present instance it is our intention to -illustrate a group of fungi which are exceedingly common, and which -differ greatly in appearance and structure from any to which we have had -occasion to allude. To obtain a general knowledge of these forms let our -reader proceed at once to a clump of rank grass; if it is his fortune to -dwell in the country, the walk of a few yards will suffice. Let him -examine this clump more carefully, perhaps, than he has been accustomed -to do, and we venture to predict that he will find some of the leaves -covered with what appears to be a dirty white mould, or mildew (Plate -XI. fig. 235). One of these leaves should be collected as carefully and -conveyed to the microscope as speedily as possible, taking care not to -touch, or brush it against any other object so as to disturb the -arrangement of the delicate little threads upon its surface. If a small -portion, say about an inch, is cut from this leaf with a sharp pair of -scissors, and laid upon a slide, or pinned down upon a strip of sheet -cork, so as to keep it flat, and then submitted to examination under the -microscope, with an inch power, a beautiful forest of crystalline -vegetation will be observed. If the examiner on this occasion should not -possess a binocular microscope we are sorry for him, because in that -case he will not see all that is to be seen under the greatest -advantages. If we ever truly enjoy looking through such an instrument, -it is on an occasion like this, when a low power is all that is needed, -and the object is required to be seen in relief. It is scarcely possible -to convey an adequate idea of the beauty of such a scene as the -microscope reveals upon this fragment of grass-leaf. Little bundles of -delicate threads, clear and crystalline, are seated upon a slender -branching mycelium. These threads, sometimes erect, sometimes drooping, -flexuous, or prostrate, are composed of numerous roundish or spherical -cells attached to each other in a moniliform or bead-like manner (fig. -236). These easily separate from each other. Let a portion of the -threads be removed from the leaf on the point of a lancet and laid upon -a glass slide, with a thin cover over them. Submit this object to a -quarter-inch power, as a drop of water is let fall at the edge of the -cover and insinuates itself, by capillary attraction, between the two -plates of glass. So soon as it touches the moniliform threads, the -disunion commences, and almost before they are enveloped in the fluid, -two spherules will scarce remain attached to each other. This delicate -little mould on the grass leaf at one time bore the name of _Oidium -monilioides_. It is now regarded only as a condition of another minute -fungus, to which attention will shortly be directed. - -The vine disease, so fearfully destructive on the Continent, and not -altogether unknown in this country, is another of these incomplete -fungi. From an individual who at the time of its first discovery in the -south of England took considerable interest in the subject, it was -called _Oidium Tuckeri_, which name it continued to bear, both here and -abroad, until, with many others, probably nearly all of the same genus, -it was found to be only a barren state of what is called by mycologists -an _Erysiphe_. The real discoverer of this mildew was undoubtedly the -Rev. M. J. Berkeley, who has successfully devoted a long life to the -study of these minute organisms, through evil and through good report, -and when that study was beset with more difficulties, and received less -encouragement than at present. If, towards the autumn, we should again -collect some whitened, mouldy, or mildewed grass-leaves, similar in -appearance to those mentioned above, and carefully look at them with a -pocket lens, little black points, almost as small as a pin-point, or -more resembling the full stop with which, this sentence closes, will be -found scattered over the white threads. The aid of the microscope must -be again sought to make out the structure of the little black dots. -Closely nestling upon the mycelium, the little points will prove to be -spherical brownish, conceptacles, surrounded with transparent floccose -appendages. Many other species are far more beautiful than that of the -grass-leaf, as will be seen by reference to our plate. The variation -consists chiefly in the form of the appendages which spring from the -conceptacle and surround it in a radiating (as in figs. 219, 222, 225, -and 230), or in a more or less confused and entangled manner (as in -figs. 216, 240, 245, and 251). The surface of the conceptacle is -minutely reticulated, and its base is attached to the mycelium. When -first formed, these globose conceptacles are almost colourless; they -afterwards acquire a yellow colour, and are ultimately of a deep brown. -The appendages are seldom at all coloured. Within the conceptacle are -contained from one to several transparent obovoid sacs, or spore-cases, -called _sporangia_, enclosing a definite number of spores (figs. 218, -224, 228, &c.), which vary in different species. In the hazel mildew, -for instance, there are two spores in each _sporangium_; in the willow -mildew four; in the maple mildew eight; in the grass mildew, and some -others, numerous. The tips of the appendages are variable, and often -elegant (figs. 227, 231, 233, 234, and 247), sometimes simple and at -others symmetrically branched. All the species occur on the still living -and green parts of plants, especially the leaves, and are therefore -truly parasitic. A pocket lens will show whether any conceptacles are -present on any suspicious leaf which may be collected, but high powers -of the microscope are essential for their complete examination. It is -during autumn, when vegetation begins to languish, that we shall be most -successful in searching for specimens. They will then be found almost -everywhere, and the white mycelium forms an object too conspicuous for -them to be readily overlooked. Botanically, nearly all the species were -at one period included in one genus, under the name of _Erysiphe_, a -name derived from the Greek, and signifying “mildew;” at the present -time they are distributed through several genera, the chief distinctions -of which are based upon the form of the appendages. Though personally -disposed to question the generic value of such distinctions, it would be -imprudent to adopt any other names here than those to be found in recent -English works on fungi. - -The first species in our enumeration is found on cultivated roses. What -a deplorable picture does a favourite rose-bush present when attacked by -this mildew! The leaves blistered, puckered, and contorted; their -petioles and the peduncles and calyces of the flowers swollen, -distorted, and grey with mould; and the whole plant looking so diseased -and leprous that it needs no mycologist to tell that the rose is -mildewed. The conceptacle in this species is minute, and contains but -one sporangium, which is one of the characters of the genus in which it -is now included, and a more justifiable distinction than the -ramifications of the appendages. The mycelium is rather profuse, and the -threads or appendages which spring from the conceptacle are simple and -floccose (fig. 216). The sporangium contains eight ovate spores. This -species (_Sphærotheca pannosa_, Lev.), in its oidioid or conidiiferous -form, was for some time known under the name of _Oidium leucoconium_. - -An allied species constitutes the hop-mildew, a visitation with which -some of our Kentish friends are too familiar. This is not a prejudiced -species in the choice of its habitation, since it is found on many other -plants, where it flourishes with equal vigour. The meadow-sweet, burnet, -scabious, teasle, dandelion, and other composite plants, plantain, and -plants of the cucumber family, all suffer more or less from its roving -disposition. The mycelium of whitish threads is even more conspicuous -than in the last species, but the conceptacles are often not to be found -at all. These are also very minute and most common on the under surface -of the leaves. The appendages, or fulcra, are simple, floccose (fig. -217), and coloured. The sporangia are found singly in each conceptacle, -and each, sporangium contains eight spores. - -An autumnal stroll amongst hazel-bushes, when the nuts are ripe, will -lead, if the nuts are not a greater attraction, to the discovery of -whitish, patches on the under surface of the leaves, caused by the -mycelium of the hazel mildew (_Phyllactinia guttata_, Lev.). These -patches are less distinct and conspicuous than in many other species, -but the little blackish dots of the conceptacles may be distinguished by -sharp eyes without the use of the lens. Though possessing a decided -preference for the hazel, this species is also found on the green leaves -of the hawthorn, ash, elm, birch, sallow, beech, oak, and hornbeam. The -conceptacles are larger than in the two preceding species, and somewhat -depressed above. The appendages are few (fig. 219), radiating, rigid, -and acicular, or like needles. Each conceptacle contains eight or more -sporangia, and each sporangium has from two to four spores (fig. 220). -This species being very common, its conceptacles large, and produced -copiously, and its appendages distinct, it will prove a good type with -which the student of these fungi may commence his examinations. This is -the only representative which we possess of the genus established by M. -Leveille for such of the _Erysiphei_ as have the conceptacle depressed, -and the appendages rigid and simple; by which features it is -distinguished from genuine species of _Erysiphe_. - -Two species, also common, having many features agreeing with each other, -are found on the leaves of the maple and the willow. The willow blight -(_Uncinula adunca_, Lev.) is found irrespectively on various species of -poplar and willow (fig. 221). In size and external appearances, to the -unaided eye, it seems scarcely to differ from the preceding, but more -minute examination will show that in the appendages there is an -appreciable difference. Still rigid, but no longer aciculate, the tips -bent or curved like a little hook, or curled upon themselves (fig. 223), -radiating and numerous (fig. 222), and at length tending upwards. Many -sporangia are contained within each conceptacle, each of which is -furnished with four spores. The amateur must not be disappointed, if, on -examining mature conceptacles with a view to the discovery of the -sporangia, he finds only free spores. The investing membrane is very -delicate, and disappears generally as the spores are matured. - -The “blight” or “mildew” which occurs on the common hedge-maple, as well -as on sycamore leaves, is exceedingly conspicuous when occurring on the -former plant. The whole bush often presents a hoary appearance as if -sprinkled with powdered chalk. In the spring, the under surface of the -leaves of the same plant are liable to become hoary from another cause. -The whiteness occurs in patches, has often a pinkish or violaceous tint, -and glistens like hoar-frost. This affection of the leaves was, at one -time, believed to be produced by a fungus which was called _Erineum -acerinum_, but now it is regarded as a diseased state of the tissues. In -the maple mildew, both surfaces of the leaves are alike affected, and -the little, dark, point-like conceptacles will be found studded over -both. It is not uncommon to meet with very white leaves, caused by the -mycelium, but which bear no fruit. The appendages in this species are -shorter than in the last (fig. 225), and the tips are bifid (fig. 226), -or divided into two short branches, each of which is bifid, and uncinate -or hook-shaped (fig. 227). The conceptacles contain not less than eight -sporangia, each of which encloses eight spores. - -Amongst the parasites that prey upon the much abused berberry (which has -been charged in turn with producing the mildew in corn), is one which -causes the green leaves to assume a chalky appearance (fig. 229), though -less conspicuously than in the maple blight. This parasite is the -berberry mildew (_Microsphæria berberidis_, Lev.). In such localities as -the writer has met with the berberry suffering from mildew, he has -invariably found a larger proportion of leaves with the barren mycelium -than of those on which the conceptacles were developed. Perhaps in other -localities this may not be the case. The appendages, as will be seen on -reference to our plate, differ materially from any of those to which we -have referred; indeed, this genus (or sub-genus) has the most elaborate -and beautiful forms in these appendages of any of the Erysiphei. A -figure is given of the tip of a fulcrum from a continental species (_M. -Ehrenbergii_, Lev.), not yet found in this country (fig. 233). In the -berberry blight the appendages are straight at the base, but afterwards -become forked, each fork being again forked, and these yet again -branched in a similar manner (fig. 230); so that a complex dichotomous -tip is formed to each of the appendages (fig. 231). Each conceptacle -contains about six sporangia, and each sporangium contains from six to -eight spores (fig. 232). - -The common gooseberry is also liable to a visitation from an allied -species, in many respects closely similar, but differing in having the -tips of the appendages more branched, and the extremities of the -ultimate branchlets are not entire and attenuated, as in the berberry -mildew; but divided into two toothlike processes. The conceptacles in -this species contain from four to eight sporangia, each of which has -four or five spores. - -In England, the leaves of the guelder-rose, and in France (perhaps also -in this country) those of the alder, nourish a parasite belonging to -this division. This “blight” possesses so much in common with others to -which allusion has been made, that it will scarcely be necessary to -describe it in detail. A figure of the tip of one of the appendages of -the variety found on the alder is given in the Plate XI. fig. 234. - -We have found another species which had not been before noticed in this -country (_M. Hedwigii_, Lev.), on the leaves of the mealy guelder-rose -in the vicinity of Darenth Wood, near Dartford, in Kent. The mealy -character of the leaves of this plant, and the minute size of the -conceptacles of the parasite, render it difficult to find; indeed, it -could not be noticed unless it were sought for, as we sought it, lens in -hand. It only occurs on the under surface of the leaves: the mycelium is -very web-like and fugacious, the conceptacles minute, globose, and -scattered (fig. 243). Four sporangia, each containing but four spores -(fig. 244), are enclosed in each conceptacle, which is surrounded by a -few appendages (about six) thrice dichotomous, and thickened at the tips -of the ultimate branches, which are incurved (fig. 247). - -The species of true _Erysiphe_ are distinguished botanically from the -foregoing by the floccose character of the appendages, in which feature -they accord with the species found on the rose and the hop, but from -which they differ in the conceptacles containing numerous sporangia -instead of only one, as in those species. - -One of the most common and conspicuous of these is found on the leaves -and leaf-like stipules of the garden pea. Every leaf in a crop will -sometimes suffer, and the gardener, to his great mortification, finds -that the mildew is more prolific than his peas. The leaves become sickly -and yellow as the mycelium of the fungus spreads over them, when they -present a peculiar appearance, as if growing beside a chalky road in dry -dusty weather, and had become covered with comminuted chalk. Soon the -conceptacles appear, profusely scattered over the white threads, like -grains of gunpowder (fig. 237), and after a brief struggle for existence -the pea and its parasite die together. In this species (_Erysiphe -Martii_, Lev.), the appendages are nearly transparent, short, and much -interwoven with the mycelium (fig. 238), the globose sporangia -containing from four to eight spores (fig. 239). It is not confined to -peas, although that habitat has been here given for it, because it is so -common upon them. Beans, melilot, St. John’s-wort, some umbelliferous -plants, and the meadow-sweet, have all been found affected. - -The species found on grasses, especially the cocksfoot, has been already -alluded to. The conceptacles contain from twenty to twenty-four ovate -sporangia, each enclosing eight spores. The appendages and mycelium are -much interwoven. - -Another of these “white mildews,” not only on account of its frequency -of occurrence on certain plants, but also from the numerous species of -phanerogamous plants on which it is found (fig. 240), may be truly -designated “common” (_Erysiphe communis_, Lk.); many kinds of crow-foot, -especially _Ranunculus acris_, are subject to its parasitism. It is -found also on other plants of the same natural order, on the -rest-harrow, trefoils, enchanter’s nightshade, bindweed, and knotgrass. -There are from four to eight sporangia in each conceptacle, containing -from four to eight spores (fig. 241). In this species, more especially, -M. Tulasne found curious sucker-like processes developed on the threads -of the mycelium (fig. 242): their office may probably be only that of -attachment. - -Of the other species found in Britain an enumeration will suffice, since -they contain no feature of interest to the microscopist; and all the -members of this section are far less beautiful than those in other -genera (especially _Microsphæria_). - -The leaves of the dogwood or cornel (figs. 245, 246) are the home of one -species (_E. tortilis_, Lk.), and the burdock of another (_E. -Montagnei_, Lev.). Both of these, in addition to the above, have -sporangia which contain more than two spores. There are also two species -in which only two spores are contained in each sporidium. One of these -(_E. Linkii_, Lev.) is found on both surfaces of the leaves of the -mugwort (figs. 248, 249); the other (_E. lamprocarpa_, Lev.) occurs on -salsafy, scorzonera, weasel-snout, and plantain (figs. 250, 251). - -These complete the _Erysiphei_; but there are allied species of too much -interest not to be noticed in connection with them. Three very singular -fungi are found on damp straw and paper; two on the former and one on -the latter. Of the species occurring on straw, the most common one is -figured, natural size, in our plate (fig. 257); but from this no idea -can be formed of its structure, which in some points resembles an -_Erysiphe_. The conceptacles are thin and brittle, and are clothed -externally with long dark-coloured branched hairs (figs. 258, 259). The -conceptacle contains long narrow sporangia, each enclosing dark, almost -black, lemon-shaped sporidia. For low powers this is a very interesting -object. The minute structure affords no feature of popular interest. -This fungus (which bears the name of _Chætomium elatum_) is common on -old straw, thatch, reeds, matting, &c., resembling small brown tufts of -hair, visible to the naked eye. - -Paper much exposed to damp will occasionally develop a similar -“bristle-mould,” surrounded by a yellowish spot (_Chætomium chartarum_, -Ehrb.); but it is not so common as the last. In habit and structure it -is very similar (figs. 252, 253). - -In 1838, the Rev. M. J. Berkeley announced the discovery by him of a -singular production, for which he was unable to find a fitting location -in any genus then established, and for which he accordingly -characterized a new one, under the name of _Ascotricha_. This new -species of paper mildew was found by him on some printed paper in a box. -It somewhat resembles the other species above alluded to, at a casual -glance; but more minute examination will reveal its differences. The -author to whom we are indebted for this species thus describes its -development. At first it appears as a minute branched mould interspersed -with globose brownish conidia. As it advances in growth, globose black -peridia become visible amongst the threads, clothed with and supported -by alternately branched obscurely-jointed filaments, the branches of -which generally form an acute angle with the stem (fig. 254). The -ramification of these is very peculiar, the stem and main shaft of each -sub-division being almost constantly shortened and surmounted by the -branches given off near its apex; this, again, is often abbreviated and -another branchlet given off, which again surpasses it; and occasionally -the same circumstance takes place a third time. The apices are clavate -and colourless; the rest of the filaments, when viewed by transmitted -light, brown, even, and pellucid: a few globose conidia are usually -attached to them (fig. 255). The conceptacle is thin, black to the naked -eye, of an olive-brown under the microscope, filled with a mass of -linear extremely transparent asci (fig. 256), each containing a single -row of broadly elliptic chocolate sporidia. These have a paler border; -sometimes the colour entirely vanishes, either from age or abortion, and -there is only a minute globose nucleus or more probably a vesicle of -air, in the centre; occasionally they become so transparent that the -globular bodies alone are visible. After the conceptacles burst, several -are frequently collected together into an irregular linear body, which -consists principally of the conglomerated sporidia. - -One other very common and troublesome little fungus (_Eurotium -herbariorum_) will for the present close our examples. This is found -creeping over dried plants preserved in herbaria, on decaying fruit, -preserves, and various other substances, sometimes animal as well as -vegetable, but chiefly the latter. To the naked eye it appears as a -myriad of little yellow spherical bodies, of the size of very small -pins’ heads, resting upon fine cobweb-like threads (fig. 260). When -magnified, the surface of the conceptacles is seen to be reticulated -(fig. 261). In the interior the sporidia are borne, contained also, as -in the former instance, in asci. It has been considered _probable_, but -as yet not fully proved, that this mildew is a compound fruited -(ascigerous) condition of an equally common mould (_Aspergillus_). - -Dr. Shortt, of Chingleput, in a recent report on the growth and -production of Indian Cotton, remarks that the plants are subject to the -attacks of a kind of mildew. He writes:—“They appear in the form of -rounded fibres or thallus, shooting up in the air, having the lamina of -the leaf as a base, and feeling villous to the touch. The small fibrillæ -that form the nap appear shooting up as sharp projections when seen by -the naked eye; under the microscope they are found to consist of pointed -tubes, interspersed here and there with minute granular cells. It first -attacks either the upper surface of the petioles, or the margins of the -leaf, gradually extending over the lamina, and matting together the -whole leaf into a greyish-white, felty mass. At first it attacks the -young shoots and tender leaves, preventing them from expanding. The -extension of the parasite deprives the plant of its juices, and -eventually either destroys or renders it sterile. The spores seem to be -derived from the atmosphere, and finding the plant in a state fit to -receive them, from either the results of excessive cultivation, or from -the effects of heat and want of moisture rendering it unhealthy, and -thus favouring the reception of the spores of the fungi. Another variety -speckles the leaves with whitish dots. These remain separate, but the -lamina is covered with them, and in time the leaf changes colour, -becomes yellowish, and eventually dies away. This is evidently the -disease called _Bunt_, or some variety of it, as it is seated beneath -the epidermis, and eventually the spores escape. Under the microscope -they seem to consist of small dark cells or spots attached to a -thread-like mycelium.” - -The writer seems certainly to have made a mistake in its affinities, and -on the faith of the above quotation we should be more disposed to regard -it as an _Erysiphe_. It is to be hoped that specimens of the affected -leaves will be forwarded to this country for examination. - - ------------------------------------------------------------------------- - - - - - CHAPTER XIII. - - _SUGGESTIONS._ - - -IF, in offering a few practical suggestions, we either repeat ourselves, -or communicate common-place hints, those who may know already all we -shall essay to tell them will please to pardon and pass on. - -All the information essential under this head relates to collecting, -examining, and preserving microscopic fungi. - -Collecting does not differ, except in the objects themselves, from any -other botanical collecting. Those who attempt it must be prepared to -sacrifice their kid gloves and patent-leather boots, to put on -waterproofs and perseverance, and come home sometimes disappointed. The -requisites for good work are but few, and easily supplied. A strong -knife, a pocket lens, and a box or leather bag, will be all that is -really essential. But where shall we go—and when? Hedge-banks, the sides -of ditches, borders of woods, anywhere, if the plants are to be found on -which the fungi are parasitic. We flatter ourselves on being rather -successful in collecting, and our favourite localities have always been -the dampest places in woods, railway-banks, and waste places. It is a -great mistake to endeavour to go over a large tract of ground. We have -spent a whole day in a little chalkpit, which had fallen into disuse, -and grown wild. Fifty yards into a wood is as much, as we attempt, when -alone; and a spot six yards square has afforded us occupation for hours. -It is better to examine a small space thoroughly than to scamper on, -mile after mile, and find nothing. - -When? is as much to be noted as where! All the year round we shall be -sure of finding something of interest. As soon as the last patch of -winter’s snow has melted from the ground, and green leaves begin to -unfold themselves, the search may begin. Cluster-cups (_Æcidium_) will -be the earliest forms encountered. On the leaves of _Lapsana communis_, -and the pilewort, these will be found before the majority of plants have -burst their buds. Henceforth, other forms will gradually appear, until -May or June. One or two species of _Puccinia_ will be seen in April or -May, but from that period until autumn, species of _Trichobasis_ will be -common. In June and July the smuts belonging to the genus _Ustilago_ are -most plentiful, and from August to October _Puccinia_ and its allied -genera will have the ascendant; so that from March to October there is -continually succeeding each other some species of parasitic fungus -belonging to the Uredines. From October to March need be no more a -season of repose from the search of these minute plants than from March -to October. So long as the ground is not covered with snow there will -always be something to find on dead leaves, rotten sticks, &c., when -there is not a green leaf to be seen. But these belong to a section to -which we have studiously avoided all reference in the foregoing pages. - -General instructions will not always apply; but in most instances, the -lowest and earliest leaves, in which vitality appears to decline, will -be most likely to suffer from the attacks of fungi. This rule must not -be too stringently applied; the species of _Æcidium_, for instance, will -generally be found on vigorous green leaves. - -Having found a plant infected with some rust or brand, and by means of a -pocket lens assured yourself that it is such, although the power is -insufficient to tell what it is, collect as many leaves as you are -likely to require; place them flat one upon the other, to prevent their -curling up at the edges, should the weather be hot, and yourself far -from home, and lay them in your box; or if you should take in preference -an old book with stiff covers, place them separately between the leaves -of your book, and they will be in still better condition, if you desire -to preserve them. Arrived at home with the results of your trip, proceed -at once to lay them between folds of blotting-paper, submit them to a -gentle pressure, and change the papers daily until your leaves are dry, -not forgetting to keep a scrap of paper with each collection, stating -date and locality, to which, after microscopical examination, the name -may be added. When thoroughly dry, your leaves may be preserved for -reference in old envelopes, with the particulars endorsed on the -outside. Fungi on leaves will generally be examined to the greatest -advantage in the fresh state, but if too much pressure is not employed -in the drying, it will not be difficult even in that condition to make -out their characteristic features. Care must be taken, by changing their -position, that moulds of other kinds do not establish themselves upon -the specimens in drying, or that when dried they do not fall a prey to -_Eurotium herbariorum_. - -If it is intended to add these leaves to your herbarium, or to form a -special herbarium for them, they should be mounted on white paper, first -by affixing one or two leaves by means of thin glue to a paper about -four inches square, on which the name, date, and locality may be -written, and attaching several of these _species_-papers to a larger or -_genus_-paper, or by devoting each larger paper to a species, adding in -future other varieties, and enclosing all the _species_-papers of the -same genus within a folded sheet, on which the name of the genus is -written. - -We have adopted, for our own herbarium, the “foolscap” size. A sheet of -paper receives within its fold the specimens of a single species; these -are affixed to the right-hand page, when the sheet is open, and a small -envelope is attached by its face to the same page at the bottom, in -which loose specimens are kept for minute and special examination, or as -duplicates. When the sheet is folded, the specific name is written at -the right-hand lower corner, or, what is better, a strip containing that -name and its number is cut from a copy of the “Index Fungorum,” kept for -the purpose, and gummed in its place. The remainder of this page, which -is of white cartridge paper, is occupied with memoranda referring to the -species enclosed, sketches of the spores, synonyms, references to -descriptions, &c. All the species-papers of each genus are placed -together within a sheet of brown paper, half an inch larger in each -direction, with the name of the genus written at the left-hand corner. A -piece of millboard, the size of the covers when folded, separates each -order. - -When a leaf, or other portion of a plant, is to be examined under the -microscope, with the view of determining the genus and species of its -parasite, it may be fastened with small pins to a piece of sheet cork, -two or three inches square, and about one-eighth of an inch in -thickness, such as used for lining entomological cabinets, and so placed -under a lens that it may easily be brought into focus, and both hands -left at liberty; or a dissecting microscope may be used for the purpose. -From one of the pustules the spores may be removed on the sharp point of -a penknife, and placed in a drop of water on a glass slide. A thin glass -cover is placed over the drop of water, and the slide is submitted to -examination. For further satisfaction it will often be found necessary -to make carefully a thin section of a pustule, and place this under the -microscope, a more troublesome but also much more satisfactory method. -Reference to the Appendix will soon determine the name and position of -the fungus, provided it belongs to the section to which this volume is -devoted. - -If it is thought desirable to mount the spores as permanent objects, -there is no obstacle to such a proceeding. The spores of the different -species of _Aregma_, of _Triphragmium_, and many of the _Pucciniæ_, will -be worth the trouble. We have tried several media, and only adopted -Glycerine or Balsam; either of these, especially the former, if the -greater difficulty of securely closing can be overcome, will answer the -purpose. - -It should be remarked that in the examination of moulds, such as those -of the genus _Peronospora_, included in this work, if any fluid be -added, the acrospores are immediately disconnected from the threads, and -float in the medium; so that if their mode of attachment or arrangement -would be studied, that must be achieved without the addition of any -fluid whatever. - -The best methods of observing germination, the production of zoospores, -&c., have been detailed already. - -Thus do we arrive at the close of the task which we had set ourselves to -perform. This fragment of a history of microscopic fungi goes forth to -plead for students, and prepare the path for somewhat more complete. Is -it not a shame that more than two thousand species of plants (never mind -how minute, how insignificant) should be known to exist, and constitute -a flora, in a nation amongst the foremost in civilization, and yet be -without a complete record? It is nevertheless true that hundreds of -minute organisms, exquisite in form, marvellous in structure, mysterious -in development, injurious to some, linked with the existence of all, are -known to flourish in Britain without a history or description, in the -language of, or produced in, the country they inhabit. It is also true -that the descriptions, by which they should be known, of hundreds of the -rest lie buried in a floating literature whence the youthful and ardent -student needs, not only youth and ardour, but leisure and perseverance -unlimited to unearth them. This, however, by the way; we may be too -great dotards on our native land, and foolish in our desire to see her -in advance, and not in the rear in scientific attainments, pursuits, and -productions of other and, perhaps, less favoured nations. - -Already we fear that some of our readers will have thought our story of -rust, brand, and mildew interminable, and looked anxiously for the -close. On the other hand, we would flatter ourselves into the belief -that some have made a new acquaintance with these minute and mysterious -forms, and would fain know more. The groups of fungi which we have -endeavoured to illustrate have, with but few exceptions, one feature in -common, _i.e._, that they are parasitic on living plants. These -constitute but a small portion of the microscopical species found in -this country. To the elegant forms of mould which inhabit decaying -vegetable substances no allusion has been made. These constitute a fairy -flora of forests and gardens with features as varied, and fruits as -multiform, as those of the trees and flowers of the earth. The numerous, -and often marvellous, phases of low life developed upon dead leaves and -rotten sticks, would in description occupy a far greater space than we -have devoted to our subject. Yet, for all these, we have not spared so -much as a passing word. The treasures still left unopened are far richer -than even those we have revealed. The gates of another world have been -thrown open, but we have scarcely passed the threshold. A minutely and -elaborately illuminated page of the book of Nature has been turned, and -we have only perused a single line. We might traverse the primeval -forests of the new world, and explore the unknown regions of the old, -and not encounter so much to excite our admiration, or cause our wonder, -as lies about our feet at home; marvels which we tread beneath our feet, -or kick from our path, because they appear to be only rotten sticks, -withered grass, and decaying leaves. All this may appear as the dream of -an enthusiast, or the ravings of one on whom the moon has shone too -often. When Columbus spoke of a new world beyond the seas, which he -longed to seek and explore, some believed him duped, and others called -him mad. We write of no chimerical El Dorado, we speak of no -undiscovered world, and yet we seem to allude to wonders still unknown, -because so few have had the courage to venture upon the journey for -themselves. - -In sober earnestness, however, let us commend this pursuit to all who -possess a microscope and leisure to use it. It may be for a time the -“pursuit of knowledge under difficulties,” on account of the condition -of our literature on this special subject; but many workers will produce -more readers, and good books will come when there are more to purchase -and appreciate. It is not improbable that in more cases than have come -under our own observation, microscopists wearied of diatoms and allied -forms, or deeming themselves in possession of all that is novel or -interesting in this direction, are seeking for a new field of labour, -and a new subject to kindle up a new enthusiasm. To these we have -advised, and to any more such we continue to advise, that fungi should -have a fair trial. If variety is desired, here they will have at least -2,000 species for a knowledge of which the microscope is essential. If -they thirst for discovery, let them be assured that here also the -earnest worker is sure to meet with such a reward. Or if they would -acquaint themselves with the manifestations of Divine power as developed -in the most minute of created things, let them follow such observers as -Tulasne and De Bary, and seek the “why and the wherefore” of the -phenomena of mycetal life. - -If there should still be any hesitation whether there is in this pursuit -sufficient of the element of variety, for those who do not desire to -pursue the subject into its deepest scientific recesses, to render it -available for them, let them go to a good public library, such as that -of the British Museum, and inquire for the large illustrated work by -Corda, entitled “Icones Fungorum,” or the more recent volumes by Tulasne -(Selecta Fungorum Carpologia), and examine the figures of microscopic -fungi in either of those works, and decide for themselves. - - ------------------------------------------------------------------------- - - - - APPENDIX A. - - ---------- - - CLASSIFICATION & DESCRIPTIONS OF FUNGI CONTAINED IN THIS VOLUME. - - ------- - - - =ÆCIDIACEI=. - - Peridium elongated— - - separating in threads _Rœstelia_. - - rupturing irregularly _Peridermium_. - - Peridium abbreviated, or _Æcidium_. - semi-immersed - - Peridium immersed _Endophyllum_. - - - RŒSTELIA, _Reb._ - - _Peridium_ elongated, at length opening by lateral fissures, or a - terminal lacerated mouth. _Spermogonia_ on the opposite surface, - on the same or on different leaves. - -=Rœstelia cancellata=, Reb. PEAR-LEAF RŒSTELIA; spots yellow, then red, -prominent; peridia split to the base into laciniæ, which remain united -at the apex.—On Pear leaves. Not very common. Autumn. (Plate II. figs. -20, 21.) - -=Rœstelia cornuta=, Tul. HORN-LIKE RŒSTELIA; spots rusty-brown; peridia -cylindrical, slightly curved, yellowish-brown; spores greyish, at length -brown.—On the under surface of the leaves of Mountain-Ash. Not common. -August. (Plate II. figs. 18, 19.) - -=Rœstelia lacerata=, Tul. LACERATED RŒSTELIA; peridia clustered in -tufts, brown, elongated, splitting to the base in segments; spores light -brown.—On the under surface of the leaves, and on the petioles and fruit -of the Hawthorn. Not uncommon. May to July. (Plate II. figs. 22, 26.) - - - PERIDERMIUM, _Chev._ - - _Peridium_ elongated, at length bursting irregularly. _Spermogonia_ - scattered, conspicuous. - -=Peridermium Pini=, Chev.; peridia oblong, scattered, large; spores -orange, abundant; spermogonia vernal or autumnal, or both; spermatia -large, white.—On leaves and young branches of Scotch Fir. Common in -Scotland, occasional in England. Summer. (Plate II. figs. 27, 28.) - -=Peridermium elatinum=, Lk.; simple, immersed; peridia elliptic, pallid; -sporidia orange.—On Silver Fir, altering both foliage and ramification. -Not common. - - - ÆCIDIUM, _Pers._ - - _Peridium_ seldom elongated, opening by a terminal mouth, surrounded - by a fringe of recurved teeth, or when short bursting - irregularly. _Spores_ disposed in chains. _Spermogonia_ on the - same or the opposite surface, clustered or scattered, central or - intermixed. - - SECT. I.—_Peridia scattered_ (_not collected in tufts or clusters_). - -=Æcidium leucospermum=, DC. WHITE-SPORED CLUSTER-CUPS; spots yellowish; -peridia scattered, often covering the whole under surface; spores white, -ovate.—On both sides of the leaves of the wood-anemone. Common. June. -(Plate I. figs. 4-6.) - -=Æcidium quadrifidum=, DC. FOUR-LOBED CLUSTER-CUPS; spots brownish; -peridia scattered, occupying almost the entire under surface; spores -brown, subglobose.—On the under side of leaves of Anemone in gardens. -(Lobes at the mouth of the peridium not constantly four.) April to May. - -=Æcidium albescens=, Grev. MOSCHATEL CLUSTER-CUPS; leaf blistered, -whitish, scattered; peridia white, split into a few large teeth; spores -yellowish-white.—On leaves and petioles of _Adoxa moschatellina_. Not -uncommon. April. - -=Æcidium Epilobii=, DC. WILLOW-HERB CLUSTER-CUPS; spots obliterated; -peridia scattered, at length oval, wider above; spores orange, at length -brown.—On the under side of leaves of _Epilobium montanum_, _E. -hirsutum_, and _E. palustre_, rarely on the upper. Common. June to -August. - -=Æcidium Thesii=, Desv. BASTARD-TOADFLAX CLUSTER-CUPS; spots -obliterated; peridia scattered or biseriate; short, cylindrical, margin -irregularly toothed, erect; spores yellowish, then dingy.—On _Thesium -humifusum_. Downs near Winchester. July, 1864. Chipstead, Surrey, Oct. -14, 1864. (Plate III. figs. 50, 51.) - -=Æcidium Soldanellæ=, Hornsch. SOLDANELLA CLUSTER-CUPS; spots -obliterated; peridia solitary, scattered over the inferior surface; -spores orange.—On the under surface of the leaves of _Soldanella -alpina_. - -=Æcidium Tragopogonis=, Pers. GOATSBEARD CLUSTER-CUPS; spots -obliterated; peridia scattered, torn, wider above; spores orange, at -length black.—On stems, leaves, and involucres of common Goatsbeard. -Very common. May to June. (Plate I. figs. 1-3.) - -=Æcidium Euphorbiæ=, Pers. SPURGE CLUSTER-CUPS; spots obliterated, leaf -thickened; peridia scattered or crowded, distinct; spores orange.—On the -under surface of the leaves of Spurge. Common. May to June. - - - SECT. II. _Peridia in tufts or clusters._ - - α. _Elongatæ._ - -=Æcidium Berberidis=, Pers. BERBERRY CLUSTER-CUPS; spots roundish, -bright red; subiculum thickened; peridia in subrotund or oval patches, -often elongated; spores orange.—On leaves, peduncles, and fruit of the -common Berberry. Common. May to July. (Plate I. figs. 7-9.) - -=Æcidium Thalictri=, Grev. MEADOW-RUE CLUSTER-CUPS; collected in -roundish clusters; peridia oblong; spores bright orange.—On _Thalictrum -alpinum_. Not uncommon in Scotland. - -=Æcidium crassum=, Pers. BUCKTHORN CLUSTER-CUPS; spots yellow-brown, -subiculum thickened; peridia crowded into a roundish heap, at first -globose, yellow, at length open; spores orange.—On _Rhamnus catharticus_ -and _R. frangula_. Common. - -=Æcidium Periclymeni=, DC. HONEYSUCKLE CLUSTER-CUPS; spots variegated, -yellow and brown, subiculum thickened; peridia sometimes elongated, in -roundish or effused heaps; spores orange.—On the under surface of -Honeysuckle leaves. Not common. June to August. - - - β. _Poculiformæ._ - -=Æcidium Calthæ.= Grev. MARSH-MARIGOLD CLUSTER-CUPS; aggregate; peridia -somewhat campanulate, with numerous minute marginal teeth; spores bright -orange, subglobose or oval.—On leaves and petioles of _Caltha -palustris_. Margin of peridia pale and brittle. Rare. Spring. - -=Æcidium Ranunculacearum=, DC. CROWFOOT CLUSTER-CUPS; spots obliterated, -subiculum thickened; peridia in irregular heaps, densely crowded -together; spores orange.—On leaves of various _Ranunculaceæ_; very -common on _R. Ficaria_, not uncommon on _R. repens_, more rarely on _R. -acris_ and _R. bulbosus_. Spring. (Plate II. figs. 12-14.) - -=Æcidium Galii=, Pers. BEDSTRAW CLUSTER-CUPS; spots linear or oblong, -obscurely brown; peridia scattered, rarely aggregate, dentate, whitish; -spores white.—On the leaves of _Galium verum_ and _G. mollugo_. (Plate -II. figs. 15-17.) - -I am doubtful whether the _Æcidium_ on _Galium mollugo_ is really this -species.—(_M. C. C._) - -=Æcidium Bunii=, DC. PIG-NUT CLUSTER-CUPS; spots obliterated, subiculum -thickened; peridia in irregular subrotund or oval heaps; spores -orange.—On _Bunium bulbocastanum_ and _Pimpinella saxifraga_. Spring. - -=Æcidium Valerianacearum=, Dub. VALERIAN CLUSTER-CUPS; hypogenous, -rarely cauline, spots on a thickened subcircular or oblong base; peridia -scattered, more or less crowded, cup-shaped, tawny, margin erect, -denticulate; spores dirty-yellow.—On _Valeriana officinalis_ and _V. -dioica_. North Britain. - -=Æcidium Asperifolii=, Pers. BORAGE CLUSTER-CUPS; clusters subrotund, on -a slightly thickened subiculum; peridia scattered; spores -yellowish-white.—On leaves of various _Boragineæ_. Summer. The parts of -the leaves on which it occurs are rendered concave on one side and -convex on the other. - -=Æcidium Grossulariæ=, DC. GOOSEBERRY CLUSTER-CUPS; spots yellow, bright -red on the opposite side, with a yellow border; peridia crowded in -roundish heaps, at length brown, and surrounded with a brown area; -spores orange.—On leaves and fruit of Gooseberry and Currant. Common. -May to June. - -=Æcidium Urticæ=, DC. NETTLE CLUSTER-CUPS; spots obliterated, subiculum -thickened; peridia disposed in elongated or subrotund heaps, at first -subglobose, then gaping; spores orange.—On leaves and stems of Nettles, -distorting them very much. Common. June. (Plate I. figs. 10, 11.) - -=Æcidium Behenis=, DC. BLADDER-CAMPION CLUSTER-CUPS; spots yellow, brown -on opposite side; peridia somewhat circinating, in subrotund heaps; -spores brown.—On _Silene inflata_. Not common. Some of the peridia are -short and open, others larger and closed. - -=Æcidium Orobi=, DC. BITTER-VETCH CLUSTER-CUPS; spots yellow, effused; -peridia scattered and disposed in small heaps; spores at length -white.—On stems and leaves of _Orobus tuberosus_. Scotland. - - - γ. _Subimmersæ._ - -=Æcidium Compositarum=, Mart. COMPOSITE CLUSTER-CUPS; spots purplish, -subrotund, confluent above; peridia crowded, in orbicular patches, or -circinating, on the under surface; spores orange, oval. - -Var. _a._ _Taraxaci_, Grev.; clusters small, scattered.—On leaves of the -Dandelion. June to July. - -Var. _b._ _Prenanthis_, Pers.; spots circular or irregular, purplish; -subiculum incrassated.—On leaves of Hawkweed (_Hieracium paludosum_). -Summer. - -Var. _c._ _Tussilaginis_, Pers.; clusters round, on a thickened base; -peridia circinating.—On the under surface of leaves of Coltsfoot and -Butter-bur. Common. Autumn. - -Var. _d._ _Jacobæa_, Grev.; pustular, soon becoming agglomerated, -numerous, depressed; peridia splitting into short, brittle, -yellowish-white teeth.—On leaves of _Senecio Jacobæa_ and _Sonchus -arvensis_. June to August. - -Var. _e._ _Lapsani_, Purt.; spots purplish, irregular, confluent, on -both sides of the leaves; peridia amphigenous, in irregular patches or -scattered, not prominent, teeth numerous, minute, reflexed; spores -yellow, oval.—On both surfaces of the leaves of _Lapsana communis_. -April. Not uncommon. - -=Æcidium Saniculæ=, Carm. SANICLE CLUSTER-CUPS; spots purplish, slightly -incrassated, small, scattered, roundish; peridia in small circulate -clusters, hypogenous, and on the petioles, at first hemispherical, at -length open, margin with from 4 to 6 spreading lobes; spores yellowish, -elliptical.—On the under surface of the leaves and on the petioles of -_Sanicula Europæa_. Not uncommon. May and June. - -=Æcidium Violæ=, Schum. _Violet Cluster-Cups_; spots yellowish; peridia -in irregular heaps, seriate and scattered; spores orange, at length -brown.—On leaves, petioles, and sepals of Violets. Common. May and June. - -=Æcidium Poterii=, Cooke. BURNET CLUSTER-CUPS; spots obliterated, -clusters subrotund or elongated; peridia hypogenous and on the petioles, -circinating or scattered, immersed, margin irregularly fringed with -numerous minute teeth, soon falling away; spores yellowish, oval.—On the -under surface of the leaflets and on the petioles of _Poterium -Sanguisorba_. Rare. May and June. Dartford Brent, Kent. - -=Æcidium Geranii=, DC. CRANESBILL CLUSTER-CUPS; spots yellow and purple; -peridia in circinating clusters; spores yellow, at length brown.—On the -under surface of leaves of _Geranium pratense_ and _G. dissectum_. Not -common. - -=Æcidium Menthæ=, DC. MINT CLUSTER-CUPS; spots obliterated; subiculum -thickened; peridia scattered, emersed, or aggregate immersed; spores -orange, elliptic.—On various Mints. Common. - -=Æcidium Scrophulariæ=, DC. FIGWORT CLUSTER-CUPS; spots yellowish; -peridia in roundish circinate clusters (rarely scattered) on the under -surface; spores whitish, becoming tawny.—On the leaves of _Scrophularia -aquatica_. Thame and Sydenham, Oxon. - -=Æcidium Pedicularis=, Lobosch. RED-RATTLE CLUSTER-CUPS; spots -obliterated, subiculum thickened; peridia thickly and irregularly -clustered, subimmersed; spores dirty, pallid orange.—On petioles, -leaves, and stems of _Pedicularis palustris_. Not common. - -=Æcidium Primulæ=, DC. PRIMROSE CLUSTER-CUPS; spots obliterated; peridia -solitary, scattered, and crowded, hypogenous; spores whitish-yellow.—On -the under surface of leaves of Primroses. Not common. May. - -=Æcidium rubellum=, Pers. DOCK CLUSTER-CUPS; spots purple; peridia -circinating, centre free; spores yellowish-white.—On leaves of Dock and -Sorrel. Not uncommon in moist localities. May and June. - -=Æcidium Ari=, Berk. WAKE-ROBIN CLUSTER-CUPS; spots round, confluent; -peridia circinating, not crowded, central ones abortive.—On leaves of -_Arum maculatum_. Not common. June and July. - -=Æcidium Dracontii=, Schwein. ARUM CLUSTER-CUPS; spots pallid, -extensively scattered over the leaves, sometimes nearly covering them; -peridia large, scattered, abundant, disposed without order on the spots; -spores orange.—On _Arum triphyllum_, in gardens. Melbury, 1863 (_Rev. M. -J. B._) A North American species. - -=Æcidium Allii=, Grev. GARLIC CLUSTER-CUPS; spots pale; peridia -circinating, not contiguous; spores yellowish.—On leaves of broad-leaved -Garlic (_Allium ursinum_). June and July. - - - ENDOPHYLLUM, _Lév._ - -_Peridium_ enclosed within the substance of the leaf, bursting -irregularly. - -=Endophyllum Sempervivi=, Lév.; peridia immersed, elliptic or roundish; -spores ochraceous, becoming brownish.—On leaves of Houseleek. - - - PUCCINIÆI. - - _a._ _Spores stipitate._ - - - Spores multiseptate— - moniliform _Xenodochus_. - cylindrical _Aregma_. - biseptate _Triphragmium_. - uniseptate _Puccinia_. - - _b._ _Spores immersed in gelatine._ - - Stroma tremelloid and expanded _Gymnosporangium_. - clavate or club-shaped _Podisoma_. - - XENODOCHUS, Schl. - - Spores multiseptate, moniliform, breaking up into many distinct - articulations.—_Berk. Outl._, pp. 328. - -=Xenodochus carbonarius=, Schl. BURNET CHAIN-BRAND; scattered, in small -tufts, hypogenous; spores curved or straight, composed of from 5 to 15 -articulations; obtuse at one extremity, slightly attenuate at the -other.—On Burnet. Very rare. (Plate III. fig. 29.) - - - AREGMA, Fr. - - Spores cylindrical, multiseptate, scarcely moniliform, borne on a - long peduncle.—_Berk. Outl._, p. 329. - -=Aregma mucronatum=, Fr. ROSE BRAND; hypogenous, scattered over the -leaves in minute tufts; spores 5- to 7-septate, terminal joint -mucronate; peduncles incrassated below, fusiform.—On leaves of various -Roses. Autumn. Frequent. (Plate III. fig. 38.) - -=Aregma acuminatum=, Fr. BURNET BRAND; hypogenous, scattered in minute -tufts; spores multiseptate, terminal joint acuminate; peduncles -equal.—On Burnet leaves. July. Common. (Plate III. fig. 32.) - -=Aregma bulbosum=, Fr. BRAMBLE BRAND; hypogenous, with a dull red stain -on the upper surface; spores in large tufts, 4-septate, terminal joint -apiculate; peduncles incrassated, and bulbous at the base.—On Bramble -leaves. Autumn. Very common. (Plate III. fig. 41.) - -=Aregma gracile=, Berk. RASPBERRY BRAND; hypogenous, scattered, in small -tufts; spores 7- to 9-septate, the terminal joint apiculate; peduncles -slender.—On Raspberry leaves. Autumn. (Plate III. fig. 43.) - -=Aregma obtusatum=, Fr. STRAWBERRY BRAND; hypogenous, scattered, in -minute tufts; spores multiseptate, terminal joint obtuse; peduncles -equal.—On leaves of barren Strawberry. Autumn. Common. (Plate III. fig. -35.) - - - TRIPHRAGMIUM, Lk. - - Spores trilocular, septa mostly vertical and horizontal.—_Berk. - Outl._, p. 332. - -=Triphragmium Ulmariæ=, Lk. MEADOW-SWEET BRAND; spots obliterated; sori -at first subrotund, covered with the epidermis; at length, when the -cuticle has vanished, effuse; spores brown, subturbinate, divided by a -vertical dissepiment, shortly pedicellate.—On leaves of Meadow-sweet, -_Spiræa ulmaria_. Autumn. (Plate III. fig. 48.) - - - PUCCINIA, Pers. - - Spores uniseptate, supported on a distinct peduncle.—_Berk. Outl._, - p. 329. - -=Puccinia graminis=, Pers. CORN MILDEW; spots pale, diffuse; sori -linear, confluent, amphigenous; spores at length black, clavate, very -slightly constricted.—On the leaves and culms of corn and grass. Autumn. -Very common, and injurious to corn. (Plate IV. figs. 57-59.) - -Var. _β. Arundinis_, Grev. Sori broad; spores more constricted and with -longer peduncles.—On the leaves and sheaths of reeds. Very common. - -=Puccinia striola=, Lk. SEDGE MILDEW; spots pallid; sori linear, -crowded, distinct, subconvex; spores at length black, oblong and -slightly constricted, or obovate, and not constricted.—On Sedges, -Rushes, &c. Autumn. Common. - -=Puccinia coronata=, Cd. CORONATED MILDEW; spots pallid; sori linear, -short, crowded, not confluent, surrounded by the ruptured epidermis; -spores shortly pedicellate, pallid; the apex surrounded by obtuse -radiating teeth.—On various Grasses. Autumn. Not uncommon. (Plate IV. -figs. 60-62.) - -=Puccinia truncata=, B. and Br. IRIS BRAND; spots obliterated; sori -oblong, brown, surrounded by the scarious epidermis; spores -obovate-oblong, even, attenuated below, upper cell abruptly truncate.—On -_Iris fœtidissima_. Autumn. - -=Puccinia Asparagi=, DC. ASPARAGUS BRAND; spots none; sori -reddish-brown, generally on the stems, scattered and crowded, surrounded -by the ruptured epidermis; spores oblong, obtuse, constricted; peduncle -white, long, thread-like.—On dead stems of _Asparagus_. Autumn. - -=Puccinia Polygonorum=, Lk. POLYGONUM BRAND; spots yellowish; sori -minute, crowded into orbicular patches; spores brown-black, -obovate-oblong, frequently constricted, with the upper joint globose.—On -the under surface of the leaves of various species of _Polygonum_. -Autumn. Common. - -=Puccinia vaginalium=, Lk. KNOTGRASS BRAND; spots none; sori hypogenous, -subrotund or oblong, at first surrounded by the ruptured epidermis; -spores brown, obtusely ovate; pedicels long, filiform.—On leaves and -stems of Knotgrass, _Polygonum aviculare_. Autumn. - -=Puccinia Thesii=, Chaill. BASTARD-TOADFLAX BRAND; cauline and -amphigenous; sori blackish-brown, small, roundish, or oblong, convex, -scattered or aggregate, surrounded by the ruptured epidermis; spores -ovate, obtuse, scarcely constricted; pedicels elongated.—On _Thesium -humifusum_, in company with _Æcidium Thesii_. Chipstead, Surrey, Oct. -14, 1864. (_A. Grugeon._) - -=Puccinia Primulæ=, Grev. PRIMROSE BRAND; hypogenous, deep brown, -solitary, scattered, or concentric and subconfluent spores -obovate-oblong, slightly constricted.—On Primrose leaves. Not common. - -=Puccinia Veronicarum=, DC. VERONICA BRAND; spots yellowish; sori -subglobose, aggregate, or circinating, central one large; spores brown, -obovate-oblong, more or less constricted.—On the under surface of the -leaves of several species of _Veronica_. Not common. - -=Puccinia Glechomatis=, DC. GROUND-IVY BRAND; spots brownish; sori -subrotund, scattered, hypogenous; spots brown, rather short, -subelliptic, scarcely at all constricted.—On leaves of Ground-Ivy, -_Glechoma hederacea_. September and October. Not uncommon. (Plate IV. -figs. 73, 74.) - -=Puccinia Menthæ=, Pers. MINT BRAND; spots obliterated; sori varying in -size, hypogenous, subrotund, scattered; spores at length black, -subglobose, or angular; peduncles short.—On leaves of Mint, Wild Thyme, -Marjoram, &c. Autumn. Common. (Plate IV. figs. 69, 70.) - -=Puccinia Scorodoniæ=, Lk. WOOD-SAGE BRAND; spots obliterated; sori -small, confluent in subrotund patches, hypogenous; spores cinnamon; -peduncles very long.—On leaves of Wood-sage. Darenth Wood. Not common. - -=Puccinia Scrophulariæ=, Lib. FIGWORT BRAND; spots pallid; sori -subrotund, oblong, or linear and confluent, surrounded by the ruptured -epidermis; spores very much crowded, subglobose or oval, brownish, -plicate, but not truly septate; pedicels elongated.—On _Scrophularia -aquatica_. Penzance. Very rare. - -=Puccinia Betonicæ=, DC. BETONY BRAND; spots obliterated; sori -hypogenous, subrotund, aggregate, surrounded by the ruptured epidermis; -spores very pale-brown, short, obovate, elliptic; peduncles short.—On -_Stachys Betonica_. Rare. - -=Puccinia Vincæ=, Berk. PERIWINKLE BRAND; spots yellowish; sori -hypogenous, scattered, subrotund, surrounded by the ruptured epidermis; -spores brown, oblong, slightly constricted, lower cell rather -attenuated; peduncle very short.—On leaves of _Vinca major_. (Plate VI. -fig. 132.) Autumn. Not uncommon. - -=Puccinia Campanulæ=, Carm. CAMPANULA BRAND; spots apparently none; sori -large, irregular, crowded, for a long time covered with the epidermis, -at length surrounded by it; spores oblong-ovate, or slightly -constricted; peduncles very short.—On _Campanulæ_. Not common. - -=Puccinia clandestina=, Carm. SCABIOUS BRAND; spots yellowish; sori very -minute, distinct, but collected together in great numbers, dark brown; -epidermis evanescent; spores oblong, very slightly constricted, -pedunculate.—On _Scabiosa succisa_. Not common. - -=Puccinia Compositarum=, Sch. COMPOSITÆ BRAND; spots obliterated or -whitish; sori small, subrotund, generally hypogenous, encircled with the -ruptured epidermis; spores brown, oval, scarcely constricted.—On the -leaves of _Centaureæ_, &c. Autumn. Common. (Plate IV. figs. 67, 68.) - -=Puccinia Syngenesiarum=, Lk. THISTLE BRAND; spots obliterated; sori -minute, collected in oval blackish-brown, raised spots, covered with the -epidermis; spores brown; peduncles very short.—On the leaves of -Thistles. Autumn. Common. (Plate IV. figs. 63, 64.) - -=Puccinia glomerata=, Grev. RAGWORT BRAND; spots pale; sori roundish, -depressed, often confluent; spores oblong, very variable; peduncles -short.—On leaves of Ragwort, _Senecio Jacobæa_. Not common. - -=Puccinia variabilis=, Grev. VARIABLE BRAND; sori amphigenous, minute, -roundish, surrounded by the ruptured epidermis, nearly black; spores -variable, obtuse, cells often subdivided; peduncle very short.—On leaves -of Dandelion. Summer and Autumn. Not uncommon. (Plate IV. figs. 82, 83.) - -=Puccinia Valantiæ=, Pers. CROSSWORT BRAND; spots obliterated; sori -small, subrotund, scattered or crowded; spores pale-brown, obovate, -attenuated below, the upper segment globular, easily separating.—On -_Galium cruciatum_. Autumn. Not common. - -=Puccinia Galiorum=, Lk. BEDSTRAW BRAND; spots obliterated; sori -hypogenous, partly covered with and surrounded by the ruptured -epidermis, scattered; spores brown.—On the leaves of several species of -_Galium_ and _Asperula odorata_. Not uncommon. (Plate VIII. figs. 172, -173.) - -=Puccinia Umbelliferarum=, DC. PIG-NUT BRAND; spots obliterated; sori -small and scattered, subrotund, surrounded by the remains of the -ruptured epidermis; spores brown, broadly elliptic, much constricted; -peduncle short.—On various _Umbelliferæ_. Common. (Plate IV. figs. 71, -72.) - -=Puccinia Ægopodii=, Lk. GOUTWEED BRAND; spots brown; sori minute, -subrotund and elongated, surrounded by the ruptured epidermis, often -circinating, and forming roundish patches; spores brown; peduncles very -short.—On _Ægopodium podagraria_. - -=Puccinia Saniculæ=, Grev. SANICLE BRAND; orbicular, variable in size, -blackish-brown, scattered, rather confluent; spores very obtuse; -peduncles somewhat elongated.—On _Sanicula Europæa_. Not uncommon. -Summer and Autumn. - -=Puccinia bullaria=, Lk. HEMLOCK BRAND; spots obliterated; sori -subrotund or oblong, covered with the epidermis; spores brown, peduncle -short, nearly obsolete.—On dry stems of _Conium maculatum_ and other -_Umbelliferæ_. August and Sept. - -=Puccinia Smyrnii=, Cd. ALEXANDER’S BRAND; spots obliterated; sori -hypogenous, large, solitary, scattered, brown; spores ovoid, obtuse, -verrucose, slightly constricted, minutely pedicellate.—On _Smyrnium -olusatrum_. (Plate III. figs. 55, 56.) - -=Puccinia Anemones=, Pers. ANEMONE BRAND; spots obliterated; sori -subrotund, surrounded by the ruptured epidermis, scattered, aggregate, -and confluent; spores brown, very much constricted, consisting of two -nearly globose portions, echinulate; peduncles very short.—On various -species of _Anemone_. Very common on _Anemone nemorosa_. April and May. -(Plate IV. figs. 64, 65.) - -=Puccinia Calthæ=, Lk. MARSH-MARIGOLD BRAND; spots brownish; sori small, -subrotund, convex, surrounded by the ruptured epidermis, scattered; -spores obovate, attenuated below, slightly constricted; peduncle very -short.—On leaves of Marsh Marigold. Spring. Rare. - -=Puccinia Noli-tangeris=, Corda. BALSAM BRAND; spots irregular, -confluent, brownish; sori gregarious, reddish-brown; spores oblong, -obtuse or attenuated, distinctly apiculate, brown; peduncles -rudimentary. On leaves of _Impatiens noli-tangere_. Gathered at Albury, -Surrey, by the Rev. L. Jenyns.—(_M. J. B._) - -=Puccinia Violarum=, Lk. VIOLET BRAND; spots yellowish; sori hypogenous, -small, crowded, covered with the epidermis, then surrounded by it; -spores brown, elliptic or broadly elliptic, slightly constricted.—On -Violets. Autumn. Common. - -=Puccinia Lychnidearum=, Lk. LYCHNIS BRAND; spots yellowish; sori -subrotund or oblong, unequal, scattered, rarely confluent; spores white, -at length brown, elongated, oblong, slightly constricted.—On leaves and -stems of _Lychnidæ_, _Sagina procumbens_. Autumn. Common. - -=Puccinia umbilici=, Guep. PENNY-WORT BRAND; seated on pallid spots; -sori round, convex, compact, at length confluent in large orbicular -patches; spores subglobose, not constricted, shortly pedicellate.—On -_Cotyledon umbilicus_. Penzance, Guernsey, Corwen, N. Wales. _W. -Pamplin._ (Plate IV. figs. 80, 81.) - -=Puccinia Rhodiolæ=, B. and Br. STONECROP BRAND; spots orbicular, brown; -sori minute, crowded; spores shortly pedicellate, articulations -depressed, sometimes spuriously subdivided.—On leaves of _Sedum -Rhodiola_. Summer. Not common. - -=Puccinia Saxifragarum=, Schl. MOSCHATEL BRAND; spots obliterated; sori -subrotund, scattered, crowded and confluent, when young surrounded by -the epidermis; spores red-brown, rather short, oblong, slightly -constricted.—On both surfaces of the leaves of _Adoxa moschatellina_. -Not uncommon. Summer. - -=Puccinia Chrysosplenii=, Grey. GOLDEN-SAXIFRAGE BRAND; sori of various -sizes, few together and confluent, pale brown; spores long, somewhat -waved, much attenuated at either extremity; peduncle elongated.—On the -under surface of the leaves of _Chrysosplenium oppositifolium_. Rare. - -=Puccinia Epilobii=, DC. WILLOW-HERB BRAND; spots pale; sori hypogenous, -subrotund, crowded; epidermis evanescent; spores effuse, cinnamon, -broadly elliptic, strongly constricted; peduncles very short.—On the -leaves of _Epilobium palustre_. Not common. - -=Puccinia pulverulenta=, Grev. GREAT WILLOW-HERB BRAND; sori hypogenous, -dark brown, scattered or subconfluent, open concentric; spores minute, -obovate, slightly constricted, lower cell rather attenuated; peduncle -not very short.—On the leaves of _Epilobium montanum_ and _E. hirsutum_. -August and September. Common. (Plate IV. figs. 78, 79.) - -=Puccinia Circææ=, Pers. NIGHTSHADE BRAND; spots obliterated; sori -minute, semiglobose, crowded into subrotund patches, occasionally -confluent, generally covered with the epidermis; spores brown, oblong, -often acute, sometimes obtuse; peduncles long, thick.—On the leaves of -_Circæa lutetiana_ and _C. alpina_. Autumn. Not common. - -=Puccinia Prunorum=, Lk. PLUM-TREE BRAND; spots obliterated; sori -hypogenous, subrotund scattered, epidermis obliterated; spores brown, -peduncles very short.—On the leaves of Plum-trees. September and -October. Very common. - -=Puccinia Fabæ=, Lk. BEAN BRAND; spots none; sori subrotund, or -elongated, surrounded by the ruptured epidermis; spores at length black, -ovato-globose; peduncle slender.—On Beans. August and September. Not -uncommon. - -=Puccinia Buxi=, DC. BOX BRAND; spots none; sori subrotund, convex, -scattered; spores brown, oblong, rather strongly constricted, lower cell -slightly attenuated; peduncle very long.—On both surfaces of Box-leaves. -April and May. Not uncommon. - - - GYMNOSPORANGIUM, DC. - - Peduncles extremely long, agglutinated by gelatine into a tremelloid - expanded mass. Spores uniseptate. - -=Gymnosporangium Juniperi=, Lk.; forming a soft gelatinous, irregular, -orange mass; spores ovate or subelliptic, filled with subglobose -granules.—On living twigs of _Juniperus communis_. - - - PODISOMA, _Lk._ - - Peduncles extremely long, agglutinated by gelatine into a common stem, - spreading out above into a _clavariæform_ mass; spores mostly - uniseptate.—_Berk. Outl._, p. 331. - -=Podisoma Juniperi=, Fr.; orange, clavariæform, somewhat branched; -stroma simple; spores very long, lanceolate, filled with elliptic -granules.—On living branches of _Juniperus communis_. Not common. - -=Podisoma foliicolum=, B.; epiphyllous, brown-black masses, subglobose, -subelliptic, or irregular, consisting of radiating, crowded, very -slender, agglutinated filaments, each bearing an elliptic or clavate, -very obtuse spore, 3- to 5-septate.—On living leaves of _Juniperus -communis_. Rare. - -=Podisoma Sabinæ=, Fr.; red-brown, tuberculiform and clavate, simple; -stroma obliterated; spores obovate, uniseptate.—On living branches of -_Juniperus Sabinæ_. April. Not uncommon. - - - =CÆOMACEI=. - - Simple and free. - Without appendages, - Springing from delicate threads. _Tilletia_. - Produced in separate cells.— - Deeply seated, pulverulent, } _Ustilago_ - generally nearly black } - Superficial, yellow or brown _Uredo_. - Not enclosed in separate cells _Lecythea_. - With appendages, - Deciduous _Trichobasis_. - Permanent _Uromyces_. - Compound. - Irregular _Polycystis_. - Subglobose or shell-shaped _Tuburcinia_. - - Spores of two orders— - 1. Spherical } _Coleosporium_. - 2. Cylindrical, septate } - 1. Spherical } _Melampsora_. - 2. Wedge-shaped, compact } - 1. Concatenate, exposed } _Cystopus_. - 2. Spherical, concealed } - - - TILLETIA, _Tul._ - - Spores spherical, reticulated, proceeding from delicate branched - threads. - -=Tilletia caries=, Tul. BUNT; included within the germen; spores -spherical, rather large, black.—On wheat, filling the grains with -dark-coloured spores, fetid when crushed. Autumn. Very common. (Plate V. -figs. 84-91.) - - - USTILAGO, _Link._ - - Plant deeply seated. Spores simple, springing from delicate threads, - or in closely-packed cells, ultimately breaking up into a - powdery mass.—_Berk. Outl._, p. 335. - -_Ustilago segetum_, Ditm. CORN SMUT; produced on the receptacle and -rachis; epidermis soon ruptured; spores loose, minute, globose, -black.—On the ears of corn and grasses. Autumn. Very common. (Plate V. -figs. 98, 99.) - -=Ustilago urceolorum=, Tul. SEDGE SMUT; produced on the glumes and -utricles; epidermis soon bursting; spores in a compact mass, afterwards -breaking up, globose, rather large, granulated.—Surrounding the seed of -various _Carices_; as, _Carex prœcox_, _stellulata_, _recurva_, and -_pseudo-cyperus_. Autumn. Not uncommon. (Plate VI. figs. 109-111.) - -=Ustilago longissima=, Tul. ELONGATED SMUT; produced on the leaves in -linear, long, parallel, dirty-olive patches; epidermis bursting -longitudinally; spores globose, breaking up into minute granules, -olive-black.—On leaves of _Poa aquatica_ and _fluitans_. Summer. Common. -(Plate V. figs. 105-107.) - -=Ustilago olivacea=, Tul. OLIVE SMUT; infesting the enlarged receptacle; -epidermis soon bursting; spores olive-green, powdery, minute, mixed with -filaments.—On _Carex riparia_. Not common. (Plate VI. figs. 126, 127.) - -=Ustilago hypodytes=, Fr. GRASS-CULM SMUT; produced on the culms beneath -the sheaths, afterwards exposed; spores minute, subglobose, -brownish-black.—On the culms of various Grasses. Summer. Sometimes not -uncommon. (Plate V. figs. 100, 101.) - -=Ustilago Maydis=, Corda. MAIZE SMUT; produced on the stems, germens, -&c.; epidermis at length bursting; spores spherical, minute, -brownish-black, surface covered with echinulate warts.—On stems, &c., of -_Zea mays_. (Plate V. fig. 108.) - -=Ustilago Montagnei=, Tul. BEAKSEDGE SMUT; produced on the seeds; -epidermis bursting; spores slightly angular, small, dark-coloured, -intermixed sparingly with fragile filaments.—On seeds of _Rhyncospora -alba_. Not common. (Plate V. figs. 96, 97.) - -=Ustilago typhoides=, B. and Br. REED SMUT; prodded on the stems of -reeds, forming thick bullate patches several inches long, occupying -whole internodes, covered by their sheath; spores globose, rather -large.—On stems of _Arundo phragmitis_. Autumn. Not uncommon. (Plate VI. -figs. 128, 129.) - -=Ustilago Salveii=, B. and Br. COCKSFOOT SMUT; produced on the leaves, -forming elongated parallel sori on the upper surface; spores obovate, -rather large, rough with minute granules.—On leaves of _Dactylis -glomerata_ and other Grasses. Not common. (Plate VI. figs. 117-119.) - -=Ustilago grammica=, B. and Br. BANDED SMUT; forming little transverse -bands consisting of short parallel black lines, 1/12 of an inch or more -in length; spores globose, very minute.—On stems of _Aira aquatica_ and -_A. cæspitosa_. Uncommon. (Plate VI. figs. 120-122.) - -=Ustilago vinosa=, Tul. OXYRIA SMUT; produced on the swollen -receptacles; spores roundish, very small, and minutely papillose, -separately pellucid, in clusters, violaceous.—On the receptacles of -_Oxyria reniformis_. Uncommon. - -=Ustilago utriculosa=, Tul. UTRICLE SMUT; produced in the germen and -perigonium; epidermis soon ruptured; spores effuse, minute, globose, -purple-black.—On _Polygonum hydropiper_ and other _Polygona_. Autumn. -Not uncommon. (Plate VI. figs. 112-116.) - -=Ustilago flosculorum=, Fr. FLORET SMUT; produced within the florets; -spores minute, purplish-brown.—On the florets of _Scabiosa arvensis_. -Not common. (Plate VI. figs. 123-125.) - -=Ustilago receptaculorum=, Fr. GOATSBEARD SMUT; produced within the -receptacles; spores ovate, minute, reticulated, violet-brown, nearly -black, very profuse, filling the receptacle.—On the receptacles of -Goatsbeard. June, July. Common. (Plate V. figs. 92-95.) - -=Ustilago antherarum=, Fr. ANTHER SMUT; produced on the anthers and -germens; spores subglobose, effuse, violet.—On the anthers of _Silene -inflata_, &c. (Plate V. figs. 102-104.) - - - UREDO, _Lév._ - - _Stroma_ composed of little irregular cells forming a lentiform disk, - whose surface is covered with many layers of cells, each of - which encloses a spore; _spores_ simple, always without any - appendage.—_Berk. Outl._, p. 331. - - ------- - - * _Spores more or less yellow._ - -=Uredo Potentillarum=, DC. POTENTILLA UREDO; spots yellowish; sori -subrotund and oval, bullate, aggregate, open, confluent; spores -subglobose, subcoherent, orange.—On various _Rosaceæ_. Common. - -=Uredo Saxifragarum=, DC. SAXIFRAGE UREDO; spots pallid; sori subrotund -and oval, raised, scattered and aggregate on the under surface; -epidermis ruptured, persistent; spores subglobose, yellow.—On various -_Saxifrages_. - -=Uredo Filicum=, Desm. FERN UREDO; spots yellowish; sori subrotund, -bullate, scattered and aggregate on the under surface; epidermis at -length bursting; spores subglobose, yellow.—On Ferns (_Cystopteris_, -&c.) Not common. - -=Uredo pustulata=, P. WILLOW-HERB UREDO; spots yellowish; sori -subrotund, minute, closed, scattered and confluent on both surfaces; -spores globose, yellow.—On _Epilobium palustre_. - -=Uredo Hypericorum=, DC. ST. JOHN’S-WORT UREDO; spots yellowish; sori -subrotund, small, bullate, distinct, scattered on the under surface; -epidermis at length bursting; spores subglobose, cohering, orange.—On -various _Hyperica_. August. Not uncommon. (Plate VIII. figs. 174, 175.) - -=Uredo Caryophyllacearum=, Johnst. STITCHWORT UREDO; spots yellowish; -sori subglobose, scattered and aggregate, minute, generally on the under -surface; epidermis closed; spores oval, at length yellow.—On various -_Caryophyllaceæ_. Autumn. - -=Uredo Quercus=, Brond. OAK-LEAF UREDO; on the under surface; sori -yellow, then orange, minute, ovate, and orbicular, slightly prominent, -scattered, solitary or agglomerated into minute patches, surrounded by -the ruptured epidermis; spores subglobose, pellucid, not cohering.—On -Oak-leaves. September. Not common. - -=Uredo porphyrogenita=, Kze. BIRD-CHERRY UREDO; spots purplish; sori -subrotund, small, aggregate, hypogenous; epidermis at length ruptured; -spores coherent, subglobose.—On leaves of _Prunus Padus_. Scotland, -1863. (_Rev. M. J. Berkeley._) - -=Uredo Vacciniorum=, P. BILBERRY UREDO; spots yellow-brown; sori -subrotund, minute, aggregate, and scattered, on the under surface of the -leaves; epidermis seldom ruptured; spores ovoid, yellowish.—On -_Vaccinium Myrtillus_ and _V. vitis-idæa_. Scotland. - -=Uredo confluens=, DC. MERCURY UREDO; on the under surface, depressed, -yellow, oblong, concentric, at length confluent; spores nearly oval.—On -_Mercurialis perennis_ and _M. annua_. May, June. Common. (Plate VII. -figs. 133, 134.) - -=Uredo Alliorum=, DC. GARLIC UREDO; spots obliterated; sori linear, -oblong, and oval, on both surfaces; spores ovoid or subglobose, yellow -or whitish.—On various species of _Allium_. Common. - - - * * _Spores brown._ - - =Uredo Statices=, Desm. SEA-LAVENDER UREDO; sori few and scattered, - orbicular or oval; spores sessile, globose, brown.—On various - species of _Statice_. - -=Uredo Circææ=, A. & S. NIGHTSHADE UREDO; sori minute, crowded, -subrotund, slightly confluent, on the under surface; spores irregular, -ovate, small, ochraceous.—On leaves of _Circæa lutetiana_. June, July. -Common. (Plate VII. figs. 135, 136.) - -=Uredo bifrons=, Grev. TWIN-FACED UREDO. On both surfaces of the leaves, -often opposite, scattered, round, light brown, girt with the remains of -the epidermis; spores globose.—On Sorrel leaves (_Rumex acetosa_ and _R. -acetosella_). July, September. Common. (Plate VII. figs. 137-139) - - - LECYTHEA, _Lév._ - - _Stroma_ surrounded or sprinkled with elongated abortive spores. - _Spores_ free, invested with their mother-cell, or - concatenate.—_Berk. Outl._, p. 334. - - - * _Spores free._ - -=Lecythea Ruborum=, Lév. BRAMBLE RUST. Spots pale, brown or purple on -the opposite side, sometimes depressed above; sori subrotund, aggregate; -epidermis soon bursting; spores globose or subglobose, echinulate, -bright ochraceous-yellow.—On the under surface of Bramble leaves. July -and August. Very common. (Plate II. fig. 40.) - -=Lecythea Rosæ=, Lév. ROSE RUST; spots yellow, small, scattered; spores -sub-oval, sometimes minutely pedicellate, orange.—On Rose-leaves. July, -September. Extremely common. (Plate II. fig. 37.) - -=Lecythea Poterii=, Lév. BURNET RUST; spots obliterated, rufous on the -opposite side; sori subrotund, scattered, minute on the under surface; -epidermis bursting; spores subglobose, often pedicellate, intense -orange; barren spores pale, cylindrical, and slightly curved.—On -_Poterium Sanguisorba_. Summer. Common. (Plate III. fig. 31.) - -=Lecythea Populina=, Lév. POPLAR RUST; hypogenous; sori yellow, roundish -or oblong, surrounded by the ruptured epidermis; spores copious, -elongated or ovate.—On Poplar and Birch leaves. Summer. Common. - -=Lecythea Euphorbiæ=, Lév. SPURGE RUST; spots obliterated; sori -subrotund, small, scattered, surrounded by the ruptured epidermis; -barren spores pyriform or subglobose, pedicellate; fertile spores -subglobose, orange.—On the under surface of the leaves of various -species of _Euphorbia_, especially _E. helioscopia_ and _E. peplus_. -August. Very common. - -=Lecythea epitea=, Lév. TAWNY WILLOW RUST; sori roundish, scattered, at -first tawny, at length growing pale, surrounded by the ruptured -epidermis; spores subrotund and pyriform.—On the under surface of -Willow-leaves. - -=Lecythea mixta=, Lév. ORANGE WILLOW RUST; spots yellow; sori subrotund, -aggregate, confluent, effuse, permanently surrounded by the ruptured -epidermis; spores oblong and pyriform, orange.—On both surfaces of the -leaves of Willows. - -=Lecythea Saliceti=, Lév. COMMON WILLOW RUST; spots yellowish; sori -subrotund, solitary, or in circles, surrounded by the ruptured -epidermis; barren spores subglobose and pedicellate or pyriform; fertile -spores subglobose, orange.—On the under surface of Willow-leaves. -Autumn. Common. - -=Lecythea Baryi=, Berk. DE BARY’S RUST; sori few; cystidia with an -abrupt globose head; spores subglobose.—On leaves of _Brachypodium -pennatum_. Very rare. - -=Lecythea Valerianæ=, Berk. VALERIAN RUST; spots yellowish; sori -subrotund, small, confluent, sometimes circinating; epidermis at length -bursting; spores reddish-brown, subglobose or clavate, shortly -pedicellate.—On _Valeriana officinalis_. August. - - - * * _Spores invested._ - -=Lecythea gyrosa=, Berk. RINGED RUST; spots obliterated; sori minute, -confluent, and forming a small distinct ring; epidermis bursting; spores -globose and elongato-pyriform, yellow or pale.—On the upper surface of -Raspberry and Bramble leaves, forming a more or less perfect ring with -the centre unoccupied. September. (Plate VIII. figs. 162-164.) - - - * * * _Spores concatenate._ - -=Lecythea Capræarum=, Berk. SALLOW RUST; spots obliterated, yellow on -the opposite side; sori varied in form, here and there confluent, -surrounded by the ruptured epidermis; barren spores subglobose and -pyriform, pedicellate; fertile spores subglobose, dirty yellow.—On the -under surface of the leaves of Sallows. June to August. Very common. -(Plate VIII. figs. 160, 161.) - -=Lecythea Lini=, Berk. FLAX RUST; spots yellowish; sori subrotund, -scattered, surrounded by the ruptured epidermis; spores globose or -pyriform, sometimes pedicellate.—On _Linum catharticum_. July. Not -uncommon. (Plate VIII. figs. 165-167.) - - - TRICHOBASIS, _Lév._ - - _Spores_ free; attached at first to a short peduncle, which at length - falls away.—_Berk. Outl._, pp. 332. - - - * _Spores yellow._ - -=Trichobasis rubigo-vera=, Lév. ROUND CORN RUST; spots yellow, heaps -oval, scattered, generally on the upper surface; epidermis at length -bursting longitudinally; spores subglobose, reddish-brown, easily -dispersed.—On Grasses and Corn. Throughout the Summer. Very common. -(Plate VII. figs. 140-142.) - -=Trichobasis linearis=, Lév. LONG CORN RUST; spots yellow-brown. Sori -elliptic, then elongated and linear; epidermis bursting; spores oblong -or globose, yellow.—On leaves and sheaths of Corn and Grasses. Summer. -Common. Plate VII. figs. 143, 144.) - -=Trichobasis Glumarum=, Lév. GLUME RUST; sori minute, round, scarcely -convex, subgregarious, often confluent. Spores globose or subovoid, -orange, not pedicellate; epispore smooth.—On the glumes of Cereals. -August. - -=Trichobasis Symphyti=, Lév. COMFREY RUST; Sori minute, very numerous, -scattered, roundish, then confluent; epidermis ruptured, scarcely -conspicuous around the margin; spores subglobose, pallid orange.—On -Comfrey. - -=Trichobasis Pyrolæ=, B. WINTERGREEN RUST; spots yellowish-brown on the -opposite side; sori globose, minute, scattered or aggregate, on the -under surface; epidermis generally closed; spores subglobose, yellow.—On -_Pyrola rotundifolia_, &c. - -=Trichobasis Petroselini=, B. PARSLEY RUST; spots yellowish; sori -subrotund and oval, confluent, on both surfaces; epidermis at length -ruptured; spores globose or subglobose, occasionally obsoletely -pedicellate, pale yellow.—On various _Umbelliferæ_. - -=Trichobasis Senecionis=, B. GROUNDSEL RUST; spots obliterated; sori -solitary or regularly crowded, subrotund and oval, on the under surface, -surrounded by the ruptured epidermis; spores subglobose, orange.—On -various species of Groundsel. July. Very common. Plate VII. figs. 145, -146.) - -=Trichobasis Caricina=, B. SEDGE RUST; spots red; sori oval, minute, -scattered, surrounded by the ruptured epidermis; spores subglobose, -reddish, then brown.—On _Carex pendula_, _C. pseudo-cyperus_, &c. June -to August. Common. (Plate VIII. figs. 170, 171.) - - - * * _Spores brown._ - -=Trichobasis oblongata=, B. LUZULA RUST; spots oblong, often confluent, -yellow-brown; sori elliptic, on both surfaces; epidermis closed; spores -brown, obtuse at either extremity.—On _Luzulæ_. May to July. (Plate VII. -figs. 158, 159.) - -=Trichobasis Scillarum=, B. HYACINTH RUST; spots oblong or subrotund, -crowded into patches; epidermis bursting longitudinally; spores -rubiginous, obovate, shortly pedunculate.—On the Wild Hyacinth, &c. - -=Trichobasis Cichoracearum=, Lév. HAWKWEED RUST; on both sides of the -leaf, dark, fuscous, minute, round, scattered: spores globose, rarely -minutely pedicellate.—On Thistles and Hawkweed. July to September. -Common. - -=Trichobasis Artemisiæ=, B. MUGWORT RUST; spots obliterated, brownish on -the opposite side; sori subglobose and oval, minute, scattered, on both -surfaces; epidermis soon ruptured; spores subglobose, brownish.—On -_Artemisia vulgaris_, &c. Not common. - -=Trichobasis Labiatarum=, Lév. MINT RUST; spots yellowish and brown; -sori subrotund, scattered, subaggregate, on the under surface; epidermis -ruptured; spores subglobose, brown.—On various _Labiatæ_. August to -September. Common. - -=Trichobasis Lychnidearum=, Lév. CHICKWEED RUST; spots pallid yellowish; -sori subrotund plane, scattered on the under surface, cinnamon, at -length brownish; epidermis ruptured; spores globoso-ovoid, sessile, or -shortly pedicellate.—On _Caryophyllaceæ_. Summer and Autumn. - -=Trichobasis Umbellatarum=, Lév. HEMLOCK RUST; spots yellowish; sori -subrotund and ovate, scattered, on the under surface, surrounded by the -ruptured epidermis; spores ovate, oval, and oblong in the same heap, -brown.—On _Conium maculatum_, _Apium graveolens_, and other -_Umbelliferæ_. August and September. - -=Trichobasis Heraclei=, B. HOGWEED RUST; on the under surface, -scattered, sometimes subconfluent, roundish, light brown, girt by the -remains of the epidermis; spores obovate, with a very short peduncle.—On -_Heracleum spondylium_. June and July. - -=Trichobasis Hydrocotyles=, Cooke. FLUKEWORT RUST; without definite -spots; sori chiefly on the upper, sometimes on the under surface, -scattered, variable, roundish, erumpent, surrounded by the ruptured -epidermis; spores subglobose, at length brown; epispore rough with -minute tubercles.—On _Hydrocotyle vulgaris_. Epping, July to September, -1863 and 1864. (Plate VIII. figs. 168, 169.) - -=Trichobasis Betæ=, Lév. BEET-LEAF RUST; spots yellow; heaps subrotund -and oval, scattered and concentric, on the upper surface; epidermis at -length bursting; spores subglobose, shortly pedicellate, brown.—On the -leaves of Beet. August and September. Common. - -=Trichobasis Fabæ=, Lév. BEAN RUST; spots obliterated; sori subrotund -and oval; bullate, scattered and aggregate, surrounded by the ruptured -epidermis; spores ovoid, brown.—On Beans. August and September. Common. - -=Trichobasis Galii=, Lév. BEDSTRAW RUST; spots yellowish; sori -subrotund, aggregate, closed; spores globose, reddish.—On _Galium -verum_, _saxatile_, &c. July and August. - -=Trichobasis suaveolens=, Lév. THISTLE RUST; spots obliterated, yellow -on the opposite side; sori subrotund, nearly plane, scattered, at length -confluent, on the under surface, surrounded by the ruptured epidermis; -spores globose, brown.—On leaves of Thistles, frequently covering the -whole under surface. Summer. Common. (Plate VII. figs. 151-153.) - -=Trichobasis Polygonorum=, B. KNOTGRASS RUST; spots red-yellow, widely -effused; sori subrotund, scattered, sometimes forming a ring, epidermis -at length bursting; spores somewhat obovate, brown.—On _Polygonum -aviculare_, _amphibium_, and other species. July to September. Common. - -=Trichobasis Vincæ=, B. PERIWINKLE RUST; spots yellowish; sori small, -subrotund, and oval, on the under surface, surrounded by the ruptured -epidermis; spores oval, rather ovoid, brown.—On leaves of _Vinca major_. -May and June. (Plate VI. fig. 130, 131.) - -=Trichobasis Geranii=, B. GERANIUM RUST; spots yellowish; sori -subrotund, nearly plane, scattered or confluent; spores subglobose, -brown.—On various species of Geranium. - -=Trichobasis Violarum=, B. VIOLET RUST; spots yellowish; sori subrotund, -scattered, generally on the under surface; epidermis ruptured, -persistent; spores subglobose, brown.—On leaves and petioles of Violets. -July. Not uncommon. - -=Trichobasis Parnassiæ=, Cooke. GRASS OF PARNASSUS RUST; on both -surfaces of the leaves; sori at first bullate, at length rupturing the -epidermis, scattered, often confluent; spores globose or nearly so, -rather large, tawny brown.—On _Parnassia palustris_. Irstead, Norfolk. -September, 1864. - -=Trichobasis Epilobii=, Berk. WILLOW-HERB RUST; spots yellowish; sori -subrotund, scattered, surrounded by the ruptured epidermis, often on the -under surface; spores subglobose, brown.—On _Epilobium montanum_, &c. -June and July. - -=Trichobasis Rhamni=, Cooke. BUCKTHORN RUST; seated on definite -yellowish spots; sori occurring only on the under surface of the leaves, -scattered or collected in clusters, very minute, roundish, or oblong; -spores at length rusty brown, subglobose.—On _Rhamnus catharticus_. -Selsdon, Surrey. September 16, 1864. (_A. Grugeon._) - - - UROMYCES, _Lév._ - - _Spores_ unilocular, attached permanently to a decided peduncle of - greater or less length.—_Berk. Outl._, p. 333. - -=Uromyces Alliorum=, DC. GARLIC RUST; spots obliterated, sori linear, -oblong, or oval, amphigenous; spores subglobose, yellow.—On species of -_Allium_. - -=Uromyces Ulmariæ=, Lév. GOLDEN RUST; broad, pulverulent, on the under -surface of leaves, nerves, and petioles; spores numerous, subglobose, -bright reddish-orange.—On _Spiræa Ulmariæ_, Roses, &c. Common. (Plate -VII. figs. 147, 148.) - -=Uromyces appendiculata=, Lév. LONG-STEMMED RUST; spots yellowish-brown, -sori subrotund and oval, confluent, nearly plane, on the under surface. -Epidermis bursting, spores ovoid, brown, with a long peduncle.—On -_Leguminosæ_ and other plants. August and September. (Plate VII. figs. -149, 150.) - -=Uromyces apiculosa.=, Lév. SHORT-STEMMED RUST: spots yellow or brown, -sori subrotund, scattered, surrounded by the ruptured epidermis; spores -ovoid, brown, shortly pedunculate.—On dock and various other plants. -August and September. Common. (Plate VII. figs. 154, 155.) - -=Uromyces Limonii=, Lév. SEA-LAVENDER RUST; epiphyllous, sori bullate, -scattered or disposed in rings; spores ovate.—On _Statice limonia_. - -=Uromyces Ficariæ=, Lév. PILEWORT RUST; spots yellowish, sori scattered, -aggregate, confluent, and expanded; epidermis ruptured; spores ovoid, -brown.—On _Ranunculus Ficaria_. May and June. Common. (Plate VII. figs. -156, 157.) - -=Uromyces Primulæ=, Lév. PRIMROSE RUST; spots yellowish, sori subrotund -and oval, aggregate, on the under surface; epidermis at length bursting; -spores ovoid, brown.—On Primroses. - -=Uromyces intrusa=, Lév. LADY’S-MANTLE RUST; on the under surface, -scattered, or partially aggregate, reddish-brown, rounded, somewhat -prominent, minute, very unequal; spores roundish or oval.—On _Alchemilla -vulgaris_. - -=Uromyces Iridis=, Lév. IRIS RUST; on the under, rarely on the upper, -surface; spots yellow, sori small, pale red-brown, oblong and linear, -scattered or aggregate, scarcely convex; epidermis bullate, rarely -bursting longitudinally; spores globose or broadly elliptic, pale brown, -pellucid.—On _Iris fœtidissima_. August to September. Not uncommon. - - - POLYCYSTIS, _Lév._ - - _Spores_ irregular, consisting of several cells.—_Berk. Outl._, p. - 334. - -=Polycystis Colchici=, Tul. MEADOW-SAFFRON SMUT; sori elongated, -bursting irregularly; spores smooth or slightly papillose.—On leaves of -Meadow-Saffron. Not common. - -=Polycystis Violæ=, B. and Br. VIOLET SMUT; sori scattered, elongated, -on both surfaces of the leaves and petioles; spores more or less -globose, consisting of several cells surrounded by a common irregular -crust.—On leaves and petioles of Violets. August. Common. (Plate IX. -figs. 185, 186.) - -=Polycystis pompholygodes=, Lév. BUTTERCUP SMUT; sori varied in form, -bullate, epidermis inflated, at first entire, then bursting irregularly, -its remains surrounding the clusters; spores copious, subglobose, black, -opaque or pellucid.—On _Ranunculus repens_ and other _Ranunculaceæ_. -Summer. Very common. (Plate IX. figs. 183, 184.) - -=Polycystis parallela=, B. and Br. RYE SMUT; sori very long, linear, -epidermis bursting longitudinally, spores globose, with several -projecting nodules, dark brown.—On culms and sheaths of Rye and on the -leaves of Carices. (Plate IX. figs. 187, 188.) - - - TUBURCINIA, _Fr._ - - _Plant_ deeply seated; _spores_ multicellular, subglobose, or - conchiform. _Berk. Outl._, p. 335. - -=Tuburcinia scabies=, B. POTATO SMUT; spores globose composed of minute -cells forming together a hollow globe with one or more lacunæ, generally -attached laterally by a slender thread, olive. On Potatoes. Common. -(Plate III. fig. 54.) - -=Tuburcinia Trientalis=, B. and Br. TRIENTALIS SMUT; sori two lines -broad, bullate, containing a black mass of rather irregular depressed -subglobose spores, which are very opaque and distinctly cellular. -Hyphasma white, branched, creeping, delicate.—On leaves of _Trientalis -Europæa_. August and September. Scotland. (Plate III. figs. 52, 53.) - - - COLEOSPORIUM, _Lév._ - - _Spores_ cylindrical, septate, some separating at the joints, some of - a different nature, persistent.—_Berk. Outl._, p. 333. - -=Coleosporium Tussilaginis=, Lév. COLTSFOOT RUST; on the under surface, -prominent, crowded, generally forming circles, becoming very confluent; -spores numerous, sub-ovate, orange-yellow.—On _Tussilago Farfara_. -Summer. Common. (Plate VIII. figs. 180, 181.) - -=Coleosporium pingue=, Lév. TAWNY ROSE RUST; spots obliterated, sori -effuse, on the nerves and petioles of the leaves; spores ovoid, -yellowish-brown.—On Roses, &c. - -=Coleosporium Petasitis=, Lév. BUTTERBUR RUST; on the under surface, -minute, depressed, spreading, somewhat aggregate, subconfluent, -irregular in form; spores oval, orange, or orange-red.—On _Tussilago -Petasites_. Autumn. Common. - -=Coleosporium Campanulæ=, Lév. CAMPANULA RUST; spots obliterated, brown -on the opposite side, sori irregular, confluent, plane, on the under -surface; spores subglobose, cohering, yellow, at length pale. On leaves -of various Campanulæ. September and October. - -=Coleosporium Sonchi-arvensis=, Lév. SOW-THISTLE RUST; on the under -surface, depressed, irregular in form, scattered, partially confluent; -spores ovate, reddish orange.—On _Sonchus oleraceus_ and _arvensis_. -Summer. Common. (Plate VIII. figs. 178, 179.) - -=Coleosporium Rhinanthacearum=, Lév. COW-WHEAT RUST; spots none or -subferruginous; sori irregular, confluent, on the under, rarely on both -surfaces; spores subglobose, compact, golden-yellow.—On _Euphrasia -officinalis_, _Bartsia odontites_, _Melampyrum arvense_, &c. August and -September. Common. (Plate VIII. figs. 170, 177.) - - - MELAMPSORA, _Cast_. - - Spores of two orders, crowded into a dense compact mass, with or - without a covering, wedge-shaped. _Berk. Outl._, p. 333. - -=Melampsora Euphorbiæ=, Cast. Hypophyllous; sori of summer spores -golden-yellow, scattered, distinct, sometimes cauline; spores small, -subglobose; sori of perfect spores becoming black, small, roundish, -spores prismatic, membrane thickened above, dark brown.—On leaves and -stems of _Euphorbia helioscopia_, _E. exigua_, and other species of -spurge. Common. (Plate IX. figs. 193, 194.) - -=Melampsora Populina=, Lév. Hypophyllous, epiphyllous, or amphigenous, -at first yellow or orange; summer spores obovate-oblong, attenuated or -truncate, echinulate; paraphyses obovate, capitate or claviform, -abundant in fully-ripened sori; sori of perfect spores at first tawny -yellow, becoming black during the winter, swelling in the spring, and -becoming of a cinnamon-colour, hypophyllous, roundish, or oblong; spores -prism-shaped, 5-6 together, yellowish, smooth.—On leaves of _Populus -nigra_. Common. Spores perfected in February. (Plate IX. figs. 195, -196.) - -=Melampsora Tremulæ=, Tul. Hypophyllous; sori of summer spores -punctiform, prominent, or papillæform, numerous; spores tawny-yellow, -elliptical or obovate; paraphyses slender; sori of perfect spores -scattered, at length blackish; spores elongated, compressed, attenuated -downwards, yellowish.—On leaves of _Populus tremula_. Common. Spores -perfected during the winter. - -=Melampsora Betulina=, Desm. Hypophyllous; sori of summer spores bright -yellow or orange, oblong, cylindrical, or obovate, truncate at the base, -echinulate; paraphyses encircling or intermixed, obovate, smooth, -hyaline; sori of perfect spores confluent, of an obscure brown in the -winter, becoming of a bright orange when mature; spores elongated, -attenuated below, polygonal, ochraceous.—On leaves of _Betula alba_. -Common. Spores perfected in January and February. (Plate IX. figs. 189, -190.) - -=Melampsora Salicina=, Lév. Epiphyllous or hypophyllous; sori, or heaps -of summer spores, scattered, pale orange, bright orange, or cinereous; -spores ovato-globose, paraphyses capitate, rarely obovate; sori of -perfect spores epiphyllous, scattered or aggregate, at first -yellowish-tawny, then brownish, at length nearly black, bullate; spores -oblong, closely packed, and laterally compressed.—On _Salix viminalis_ -and _S. capræa_. Common. Spores perfected in February. (Plate IX. figs. -191, 192.) - - - CYSTOPUS. - - Receptacle consisting of thick branched threads; conidia concatenate, - at length separating; oospores deeply seated on the mycelium. - -=Cystopus candidus=, Lév. CRUCIFER WHITE RUST; conidia equal, globose; -membrane equal, ochraceous; oospores subglobose, epispore -yellowish-brown, with irregular obtuse warts; warts solid.—On -Shepherd’s-purse, Cabbages, and other Cruciferæ. Summer. Very common. -(Plate X. figs. 198-200, 205-207.) - -=Cystopus cubicus=, Str. GOATSBEARD WHITE RUST; conidia unequal; -terminal cell sterile, larger than the rest; membrane thickened, -ochraceous, rarely yellowish; fertile cells shortly cylindrical; -membrane hyaline; oospores globose; epispore brown, verrucose; warts -hollow, round, or irregular.—On goatsbeard, salsify, and scorzonera. -Summer and autumn. Common. (Plate X. figs. 201, 202, 210.) - -=Cystopus Lepigoni=, De By. SANDWORT WHITE RUST; conidia unequal; -terminal cell sterile, globose; membrane thickened; fertile cells -subglobose or cylindrical; membrane hyaline; oospores globose; epispore -brown, tubercles minute, irregular, very convex, often resembling -spines.—On _Spergutaria rubra_. Swanscombe Marshes, September, 1864. -(_R. G. Keeley._) - - - PERONOSPOREI, De By. - - PERONOSPORA, _Casp._ - - Parasitic threads mostly inarticulate. Spores of two kinds:—1. - Acrospores on the tips of the branchlets; 2. Oospores large, - globose, on the creeping mycelium. - -=Peronospora infestans=, Mont. POTATO MOULD; threads of mycelium -slender, always destitute of suckers; fertile threads thin, gradually -attenuated upwards, with one to five branches, one or more inflated -vesicles near the apices of the branches; branches either simple or with -short branchlets; acrospores ellipsoid or ovoid; apex furnished with a -prominent papilla.—On leaves, stems, and tubers of the Potato, causing -the potato-murrain. Very common since 1845. (Plate XIV. fig. 264.) - -=Peronospora nivea=, Ung. (_P. macrospora_, B.). PARSNIP MOULD; threads -of mycelium stout, often torulose; suckers numerous, vesicular, obovate; -fertile threads fasciculate, dwarfish, tapering or subulate, or once or -twice shortly bifurcate, rarely trifurcate, with one to four horizontal -branches near the summit, once, twice, or three times bifurcate; -acrospores subglobose or ovoid, with an obtuse papilla at the apex.—On -various _Umbelliferæ_. Common and variable. - -=Peronospora pygmæa=, Ung. (_P. curta_, Berk.). ANEMONE MOULD; threads -of mycelium thickened, often constricted and varicose; suckers minute, -obovate, or pear-shaped; fertile threads fasciculate (2-5 or more), -simple above or divided at the apex into 2-4 short simple branches, or -shortly twice dichotomous, or all simple, obtuse, surmounted by 2-4 -short spicules; acrospores ovoid or ellipsoid, variable in size; apices -broadly and obtusely papillate.—On Wood-anemone. Not uncommon. (Plate -XV. fig. 267.) - -=Peronospora gangliformis=, Berk. LETTUCE MOULD; threads of the mycelium -stout, now and then torulose; suckers vesicular, obovate or clavate; -fertile threads 2-6 times dichotomous, sometimes trichotomous; stems and -primary branches slender, dilated or inflated above; the ultimate ramuli -inflated at the apex into a turbinate or subglobose vesicle bearing from -2-8 subulate processes or spicules; acrospores minute, subglobose; -apices with broad depressed papillæ, produced on the spicular processes, -On Lettuces and other _Compositæ_. Frequent. (Plate XIV. fig. 265.) - -=Peronospora parasitica=, Pers. CABBAGE MOULD; threads of the mycelium -thickened and much branched; suckers numerous, branched; branches -clavate, obtuse; fertile threads thick, soft, flexile, equal or unequal, -5-8 times dichotomous, rarely trichotomous; branches always repeatedly -trifurcate; acrospores broadly elliptical, very obtuse at the apex, -white.—On Cabbages, Shepherd’s-purse, and other Cruciferæ, sometimes in -company with _Cystopus candidus_. Summer and autumn. Common. (Plate -XIII. fig. 262.) - -=Peronospora Viciæ=, Berk. PEA MOULD; fertile threads densely cæspitose, -erect, equal, rarely unequal, 6-7-8 times dichotomous; ultimate ramuli -shortly subulate, acute; acrospores ellipsoid, very obtuse at the apex, -obtuse or slightly acute at the base; membrane with a violaceous -tint.—On Tares, Peas, &c. Frequent. (Plate XV. fig. 266; Plate X. fig. -212.) - -=Peronospora Arenariæ=, Berk. SANDWORT MOULD; fertile threads slender, -6-7 times equally, rarely unequally, dichotomous; branches spreading; -ultimate ramuli slender, acute, subulate, nearly erect; acrospores -broadly elliptical, oftentimes very obtuse, small; membrane scarcely -violaceous.—On _Arenaria serpyllifolia_ and _A. trinervis_.—June. (Plate -XVI. fig. 268; Plate X. fig. 211.) - -=Peronospora effusa=, Grev. SPINACH MOULD; fertile threads fasciculate, -short, thick, 2-6, rarely 7 times dichotomous above; acrospores broadly -ellipsoid, sometimes very obtuse; membrane with a violaceous tint. On -Spinach, Goosefoot, and some other allied plants. Spring and autumn. Not -uncommon. (Plate X. figs. 214, 215.) - -=Peronospora Urticæ=, Casp. NETTLE MOULD; fertile threads small, loosely -4-6 times dichotomous; branches flexuose, ultimate ramuli subulate, -arcuate, often deflexed; acrospores large, broadly ovoid or subglobose, -distinctly pedicellate; apices very obtuse; membrane violaceous.—On -leaves of the common Nettle. - -=Peronospora trifoliorum=, De By. CLOVER MOULD; fertile threads -cæspitose, equally or unequally 6-7 times dichotomous, rarely -trichotomous; ultimate branches subulate, acute, slightly curved; -acrospores ellipsoid, very obtuse; membrane with a slightly violaceous -tint; oospores large; epispore brown.—On Lucern (_Medicago sativa_). -Highgate and Hampstead, 1864. - -=Peronospora grisea=, Ung. VERONICA MOULD; fertile threads erect, -fasciculate, grey, 5-7 times regularly dichotomous; branches gradually -attenuated; primary oblique erect; others spreading, flexuose; ultimate -mostly unequal, slightly arcuate; acrospores ellipsoid or ovoid, obtuse; -membrane pale and dirty violet.—On leaves of _Veronica beccabunga_. May, -1846. (Plate X. fig. 213.) - -=Peronospora arborescens=, Berk. POPPY MOULD; fertile threads slender, -erect, 7-10 times dichotomous above; branches more or less flexuose, -squarrose, spreading, gradually attenuated; ultimate ramuli shortly -subulate, more or less arcuate; acrospores very small, subglobose; -membrane scarcely violaceous.—On the Corn Poppy. June. Common. - -=Peronospora Schleideniana=, De By. (_P. Destructor_, B.) ONION MOULD; -fertile threads robust, erect, not septate, branched alternately; -ultimate ramuli forked and uncinate or divaricate; acrospores seated on -the tips of the ultimate ramuli, obovoid or nearly pear-shaped, -attenuated at the base; membrane of a dirty violet-colour.—On the leaves -of various species of _Allium_. Often plentiful. (Plate XIII. fig. 263.) - -=Peronospora violacea=, Berk. SCABIOUS MOULD; fertile threads branched; -acrospores sub-elliptical, violet-coloured. All that is known of this -species is contained in the following note from the Rev. M. J. -Berkeley:—“It grew on the petals of the common scabious. I have not -found it again, and have either lost or mislaid my specimens. You may -describe it as _læte violacea_; _floccis ramosis_; _sporis -subellipticis_, _violaceis_. It is probably the _Farinaria_ on Scabious -of Sowerby.” (M. J. B.) - -=Peronospora sordida=, Berk. FIGWORT MOULD; forming broad, irregular, -dirty, pallid spots on the under surface of the leaves; fertile threads -loosely dichotomous above; tips forked, unequal; acrospores obovate, -apiculate.—On leaves of _Scrophularia_. Jedburgh. - -=Peronospora sparsa=, Berk. ROSE MOULD; fertile threads scattered, by no -means torulose, ultimate branches scarcely uncinate, dichotomous, pallid -grey; acrospores sub-elliptical.—On the under side of rose-leaves in -conservatories. - -=Peronospora obliqua=, Cooke. DOCK MOULD; threads of the mycelium -slender; fertile threads fasciculate, erect, simple, rarely bifurcate, -attenuated upwards; acrospores large, ellipsoid, attached obliquely near -the base.—On the under surface of dock leaves. Winter and spring. -Probably not uncommon. Brownish circular spots on the leaves indicate -the presence of this mould, which is so minute that it might otherwise -be overlooked. (Plate XVI. fig. 269.) - - - =Erysiphei=. - - _Conceptacle with one sporangium._ - Appendages floccose _Sphærotheca_. - - _Conceptacle with many sporangia._ - Appendages needle-shaped, rigid _Phyllactinia_. - Appendages hooked _Uncinula_. - Appendages dichotomous _Microsphæria_. - Appendages floccose _Erysiphe_. - - - SPHÆROTHECA, _Lév._ - - Mycelium arachnoid; perithecia globose, containing a single globose - sporangium; appendages numerous, floccose.—_Berk. Outl._, p. - 404. - -=Sphærotheca pannosa=, Lév. ROSE BLIGHT; mycelium thickened, woolly, -felted, persistent; conceptacles minute, globose, scattered; appendages -floccose, white; sporangium many-spored.—On the branches, calyces, -petioles, and leaves of Roses. Very common. (Plate XI. figs. 217, 218.) - -=Sphærotheca Castagnei=, Lév. HOP BLIGHT; on both surfaces; mycelium -effuse, web-like, commonly evanescent; conceptacles minute, scattered, -globose; appendages numerous, short, flexuose above; sporangium -many-spored.—On the leaves of the Hop, Meadow-sweet, and various other -plants. Common. (Plate XI. fig. 216.) - - - PHYLLACTINIA, _Lév._ - - Perithecia hemispherical, at length depressed, seated on a persistent - or evanescent membranaceo-granular receptacle; appendages - straight, rigid, acicular, at length bent back.—_Berk. Outl._, - p. 404. - -=Phyllactinia guttata=, Lév. HAZEL BLIGHT; amphigenous; mycelium -web-like, often evanescent; conceptacles large, scattered, -hemispherical, at length depressed; appendages hyaline, rigid, simple; -sporangia 4-20, containing 2-4 spores.—On the leaves of Hawthorn, Hazel, -Ash, Elm, Alder, Beech, Birch, Oak, Hornbeam, and various other plants. -Common. (Plate XI. figs. 219, 220.) - - - UNCINULA, _Lév._ - - Mycelium floccose; perithecia globose; appendages rigid, simple, bifid - or dichotomous, uncinate, at length bent upwards.—_Berk. Outl._, - p. 404. - -=Uncinula adunca=, Lév. WILLOW BLIGHT; mycelium variable; conceptacles -scattered or gregarious, minute; appendages simple; sporangia 8-12, -sub-pyriform, containing 4 spores.—On the leaves of Willows, Poplars, -Birch, &c. Not uncommon. (Plate XI. figs. 221-224.) - -=Uncinula bicornis=, Lév. MAPLE BLIGHT; amphigenous; mycelium web-like, -effuse, evanescent, or like a membrane and persistent; conceptacles -large, hemispherical, at length depressed; appendages simple, bifid or -dichotomous, uncinate; sporangia 8, sub-pyriform, containing 8 -spores.—On the leaves of Maples. Common. (Plate XI. figs. 225-228.) - - - MICROSPHÆRIA, _Lév._ - - _Mycelium_ arachnoid; appendages straight, dichotomous; branchlets - swelling at the tip, or filiform.—_Berk. Outl._, p. 404. - -=Microsphæria Hedwigii=, Lév. MEALY GUELDER-ROSE BLIGHT; hypophyllous; -mycelium web-like, evanescent; conceptacles minute, globose, scattered; -appendages few, very little longer than the diameter of the -conceptacles; sporangia 4, ovate, containing 4 spores.—On leaves of -mealy Guelder-rose. Near Greenhithe, Kent. - -=Microsphæria penicillata=, Lév. GUELDER-ROSE BLIGHT; amphigenous; -mycelium web-like, effuse, evanescent; conceptacles scattered, minute, -globose; appendages 8-12, equal to the diameter of the conceptacle; -sporangia 4, ovate, rostrate, containing 8 spores.—On leaves of -Guelder-rose and Alder. Probably not uncommon. (Plate XI. fig. 234.) - -=Microsphæria Mougeotii=, Lév. TEA-TREE BLIGHT; amphigenous; mycelium -web-like, oftentimes persistent; conceptacles minute, scattered or -gregarious, globose, at length depressed; appendages loosely -dichotomous; sporangia 12-16, on a short pedicel, 2-spored.—On leaves of -_Lycium barbarum_. Near Dartford, Kent. October, 1864. - -=Microsphæria Berberidis=, Lév. BERBERRY BLIGHT; amphigenous; mycelium -web-like, oftentimes persistent; conceptacles scattered or gregarious, -globose, minute; appendages few (5-10); branchlets long, divaricate, -obtuse at their apices; sporangia 6, ovate, containing 6-8 spores.—On -leaves of the common Berberry. Autumn. Frequent. (Plate XI. figs. -229-232.) - -=Microsphæria grossulariæ=, Lév. GOOSEBERRY BLIGHT; amphigenous; -mycelium web-like, fugacious or persistent; conceptacles scattered or -gregarious, globose, minute; appendages 10-15, vaguely dichotomous, -ultimate branchlets bidentate; sporangia 4-8, ovate, containing 4-5 -spores.—On Gooseberry-leaves. Autumn. Frequent. - - - ERYSIPHE, _Hedw._ - - Mycelium arachnoid; appendages floccose, simple or irregularly - branched.—_Berk. Outl._, p. 404. - - * _Sporangia 2-spored._ - -=Erysiphe Linkii=, Lév. MUGWORT BLIGHT; amphigenous; mycelium web-like; -fugacious or persistent; conceptacles minute, globose, scattered, -emersed; appendages white, interwoven with the mycelium; sporangia 8-20, -pyriform, with elongated pedicels.—On leaves of Mugwort. Autumn. -Frequent. (Plate XII. figs. 248, 249.) - -=Erysiphe lamprocarpa=, Lév. COMPOSITE BLIGHT; amphigenous; mycelium -web-like, fugacious or persistent; conceptacles minute, globose, -scattered, or gregarious; appendages coloured, interwoven with the -mycelium; sporangia 8-16, shortly pedicellate.—On leaves of Salsify, -Scorzonera, Plantain, &c. Autumn. Not uncommon. (Plate XII. figs. 250, -251.) - - - ** _Sporangia 3-8-spored._ - -=Erysiphe graminis=, D.C. GRASS BLIGHT; amphigenous or epiphyllous; -mycelium effuse, floccose, persistent; conceptacles large, gregarious or -disseminated, hemispherical, at length depressed and semi-immersed; -appendages simple or interwoven with the mycelium; sporangia 20-24, -ovate, pedicellate, with 8 spores.—On leaves of Grasses. Autumn. -Frequent. (Plate XI. figs. 235, 236.) - -=Erysiphe Martii=, Lk. PEA BLIGHT; amphigenous; mycelium web-like, very -often evanescent, globose; appendages short, interwoven with the -mycelium; sporangia 4-8, globose, pedicellate, with 4-8 spores.—On -leaves of Peas, Beans, _Umbelliferæ_, and other plants. Autumn. Very -common. (Plate XI. figs. 237-239.) - -=Erysiphe Montagnei=, Lév. BURDOCK BLIGHT; amphigenous or hypophyllous; -mycelium web-like, evanescent; conceptacles minute, globose, gregarious -or scattered; appendages distinct from the mycelium; sporangia 8, ovate, -rostrate, with 2-3 spores.—On leaves of Burdock. Not uncommon. - -=Erysiphe tortilis=, Lk. CORNEL BLIGHT; hypophyllous; mycelium web-like, -effuse, evanescent; conceptacles minute, globose; appendages ten times -as long, free from the mycelium, flexuose; sporangia 4, ovate, rostrate, -with 4 spores.—On leaves of the common Dogwood. Autumn. Frequent. (Plate -XII. figs. 245, 246.) - -=Erysiphe communis=, Schl. BUTTERCUP BLIGHT; hypophyllous; mycelium -effuse, web-like, evanescent or persistent; conceptacles minute, -globose, scattered or gregarious; appendages short; sporangia 4-8, -ovate, rostrate, with 4-8 spores.—On leaves of various _Ranunculaceæ_, -_Leguminosæ_, and other plants. Autumn. Very common. (Plate XI. figs. -240-242.) - - - CHÆTOMIUM, _Kze._ - - Perithecium thin, brittle, mouthless; sporangia linear, containing - dark lemon-shaped spores. _Berk. Outl._, p. 405. - -=Chætomium elatum=, Kze. STRAW-BRISTLE MOULD; perithecium sub-ovate, -base radiato-fibrose, hairs of the vertex very long, interwoven, -branched; spores broadly elliptic, apiculate at either end.—On -mouldering straw, reeds, matting, &c. Very common. (Plate XII. figs. -257-259.) - -=Chætomium chartarum=, Ehb. PAPER-BRISTLE MOULD; perithecium subglobose, -black, surrounded by a bright yellow spot; spores subglobose.—On paper. -Stibbington, Hants. Rare. (Plate XII. figs. 252, 253.) - -=Chætomium glabrum=, B. This species has never been described. It was -recorded, by name only, in Berkeley’s Outlines, and, the specimens being -mislaid, that gentleman is unable to describe it completely and -correctly. “It grew abundantly on straw, and differed from _Chætomium -elatum_ in being perfectly free from hairs.”—(_M. J. B._)—On damp straw. - - - ASCOTRICHA, _Berk._ - - Perithecium thin, free, mouthless, seated on loose, branched, - conidiiferous threads; sporangia linear, containing dark - elliptic spores.—_Berk. Outl._, p. 405. - -=Ascotricha chartarum=, B. PAPER MILDEW; perithecium thin, olive-brown, -seated on radiating flocci; sporangia linear, numerous; spores broadly -elliptic, chocolate-coloured.—On white printed paper in a deal -candle-box. King’s Cliffe. (Plate XII. figs. 254-256.) - - - EUROTIUM, _Link._ - - Perithecia reticulated, vesicular, coloured, attached to mucedinous - threads; sporangia delicate.—_Berk. Outl._, p. 405. - -=Eurotium herbariorum=, Lk. HERBARIUM MOULD; perithecium spherical, -sub-depressed, yellow, seated upon radiating expanded, branched, -intricate flocci.—On plants in herbaria, and various decaying -substances. Very common. (Plate XII. figs. 260, 261.) - - ------------------------------------------------------------------------- - - - APPENDIX B. - - ------- - - -The following species, belonging to those sections of Microscopic Fungi -which are included in this volume, have been found in Britain since the -publication of the preceding Appendix:— - -=Peridermium columnare=, Alb. and Schw. Simple, slender, naked, -cylindrical, elongated, lacerated at the apex, white; sporidia -orange.—On _Picea_. Watcombe, near Torquay. September, 1867. (_E. -Parfitt._) - - * * * * * - -=Æcidium Orchidearum=, Fiedl. ORCHIS CLUSTER-CUP; spots large, pallid, -orbicular or elongated; peridia circinating, semi-immersed; spores -golden-yellow.—On _Orchis latifolia_. Dilham, Norfolk. June, 1866. - - * * * * * - -=Puccinia discoidearum=, Link. SOUTHERNWOOD BRAND; spots obliterated; -sori subrotund, minute, surrounded by the ruptured epidermis; sporidia -brown, oblong or ovoid, somewhat rhomboidal, with both cells attenuated, -and triangular; peduncles elongated.—On _Artemisia maritima_. Swanscombe -Marshes. 1865. - -=Puccinia Virgaureæ=, Lib. GOLDEN-ROD BRAND; spots orbicular, pallid, -then yellowish; sori blackish-brown, minute, punctiform, shining, -clustered, nearly stellate, convex; sporidia oblong, subconstricted, -yellowish-brown above, attenuated and yellowish-white below; peduncles -short.—On leaves of _Solidago virgaurea_. Shere, Surrey. July and -August, 1865. (_Dr. Capron._) - -=Puccinia difformis=, Kunze. GOOSEGRASS BRAND; spots yellowish; sori -variable, compact, often in rings; epidermis bullate; sporidia obovate, -obtuse, on short pedicels, brown.—On leaves of _Galium aparine_. July, -1866. Shere and Darenth Usually occurring on or near spots previously -occupied by _Æcidium_. - -=Puccinia Apii=, Corda. CELERY BRAND; sori large, confluent, red-brown, -powdery; spores oblong, constricted, brown; epispore smooth, thick; -pedicels short, attenuated.—On leaves of Celery. Autumn, 1866, 1867. - -=Puccinia Asari=, Kunze. ASARABACCA BRAND; spots obliterated; sori -small, subglobose, crowded or circinating, ultimately confluent, -surrounded by the ruptured epidermis, usually forming a large, roundish, -convex, pulverulent mass; sporidia brown, elliptic, constricted.—On -leaves of _Asarum Europæum_. Bettws-y-coed, N. Wales. July, 1866. - -=Puccinia Mœhringiæ=, Fuckel. It is very doubtful whether this deserves -to rank as a species distinct from _P. Lychnidearum_, Lk. I think not. -The sporidia are rather shorter than in the last-named species, and the -pedicels are very long; otherwise it does not appear to differ from the -typical form.—On _Mœhringia trinervis_. Near Worcester. June, 1867. -(_Dr. Holl._) - -=Puccinia fallens=, Cooke. VETCH BRAND; sori few and small, scattered, -intermixed with pustules of _Trichobasis_; sporidia obovate, on rather -long pedicels, of a tawny colour, and slightly constricted at the -septum; epispore smooth.—On leaves of _Vicia sepium_. Liverpool. Autumn, -1865. (_R. McLeod._) - - * * * * * - -=Uredo Orchidis=, Mart. ORCHIS UREDO; amphigenous; spots reddish-brown; -sori subrotund, arranged in circles, often confluent; sporidia -subglobose, golden-yellow.—On _Listera ovata_ and _Orchis latifolia_. -Crosby, near Liverpool. May, June, 1865. (_R. G. McLeod._) - -=Uredo Empetri=, D.C. CROWBERRY UREDO; hypogenous; spots obliterated; -sori oval, scattered: the epidermis at first convex, afterwards ruptured -and concave; sporidia ovoid or subglobose, bright yellow.—On _Empetrum -nigrum_. Near Llanderfel, N. Wales. May, 1865. - -=Uredo Euonymi=, Mart. SPINDLE UREDO; spots yellowish; sori roundish, -circinating, often confluent; epidermis erumpent; sporidia ovoid and -slightly coherent, tawny-yellow.—On leaves of _Euonymus Europæus_. -Darenth Wood, Kent. August, 1864. Rare. - -=Uredo Tropæoli=, Desmz. NASTURTIUM UREDO: hypogenous; spots -pale-yellow; sori minute, roundish, scattered or confluent; sporidia -ovoid or subglobose, orange.—On leaves of _Tropæolum aduncum_. Shere. -October, 1865. (_Dr. Capron._) - - * * * * * - -=Trichobasis fallens=, Cooke. CLOVER RUST; spots obliterated; sori -amphigenous, numerous, scattered, subrotund, brown, surrounded by the -remains of the ruptured epidermis; spores sub-ovate; pedicels short, -hyaline, evanescent; epispore verrucose. _Uredo fallens_, Desmz.—On -leaves of Clover, &c. September. Not uncommon. - - * * * * * - -=Uromyces graminum=, Cooke. COCKSFOOT RUST; epiphyllous; sori oblong or -confluent and linear, convex, black and shining, so as easily to be -confounded on casual observation with _Dothidea graminis_, at length -bursting longitudinally; sporidia subglobose or ovate, tawny, with -hyaline pedicels of variable length.—On leaves of _Dactylis glomerata_. -Shere. October, 1865. (_Dr. Capron._) - -=Uromyces concentrica=, Lév. Described at p. 208 as _Trichobasis -Scillarum_, B.; but it appears to be a good _Uromyces_, and has been -placed in that genus by Lévielle. - -=Uromyces sparsa=, Lév. SANDWORT RUST; spots pallid; sori subrotund and -oval, amphigenous and cauline; epidermis erumpent; sporidia ovoid, -brownish; peduncles thickened, short.—On _Spergularia rubra_. Swanscombe -Marshes. June, 1865. - -=Uromyces Polygoni=, Fuckel. KNOTGRASS RUST; cauline; sori elongated and -confluent, convex, surrounded by the remains of the ruptured epidermis; -sporidia subglobose or globose, smooth, yellowish-brown; pedicels very -long, thickened, hyaline, persistent. _Capitularia Polygoni_, Rabh.—On -the stems of _Polygonum aviculare_. October. Common. - - * * * * * - -=Cystopus spinulosus=, De Bary. THISTLE (WHITE) RUST; conidia in time -much elongated; sori erumpent on both surfaces of the leaves, white; -oospores globose; epispore brown; tubercles minute, solid, very -prominent, often acute and spinulose.—On Thistles. Bungay, Suffolk. -September, 1865. - - * * * * * - -=Peronospora candida=, Fuckel. PRIMROSE MOULD; densely cæspitose, white; -threads erect, dichotomously branched; ultimate branchlets short, -spreading; sporidia ovate.—On leaves of Primrose. Near Corwen, N. Wales. -July, 1866. - - - The following genus is entirely new to Britain. Its position is - next to _Microsphæria_ at page 219. - - - PODOSPHÆRA, _Kunze_. - -Mycelium effuse, web-like, evanescent; conceptacles sphærical, -containing one subglobose 8-spored sporangium; spores ovate; appendages -few, dichotomous, thickened at their extremities, hyaline. - -=Podosphæra Kunzei=, Lév. PLUM BLIGHT; amphigenous; conceptacles minute, -scattered, globose; appendages three times the length of the diameter of -the conceptacles.—On leaves of _Prunus domestica_. Shere, Surrey. Sept., -1865. (_Dr. Capron._) - -=Podosphæra clandestina=, Lév. HAWTHORN BLIGHT; amphigenous; -conceptacles minute, globose, scattered; appendages (8-10) equal in -length to the diameter of the conceptacles; branches short and rounded -at their extremities.—On leaves of the Hawthorn. Upper Holloway. -October, 1864; Shere, Surrey, September, 1865. (_E. C._) - - * * * * * - -=Uncinula Wallrothii=, Lév. SLOE BLIGHT; amphigenous; mycelium web-like, -evanescent; conceptacles minute, scattered; sporanges 12-16, -pear-shaped, 6-spored; appendages numerous, twice the length of the -diameter of the conceptacles.—On leaves of the Sloe, _Prunus spinosa_. -Shere, Surrey. October, 1865. (_Dr. Capron._) - - * * * * * - -=Microsphæria comata=, Lév. SPINDLE BLIGHT; hypophyllous; mycelium -web-like, fugacious; conceptacles scattered, minute, globose; sporanges -8, ovate, with a beak-like termination at their base, 4-spored; -appendages few, six times the length of the diameter of the -conceptacles.—On _Euonymus Europæus_. Shere, Surrey. August, 1865. (_Dr. -Capron._) - - * * * * * - -=Erysiphe horridula,= Lév. BORAGE BLIGHT; amphigenous; mycelium -web-like, sometimes persistent; conceptacles minute, globose, scattered -or clustered; sporanges 20-24, oblong-ovate, attenuated downwards, -containing 3-4 spores; appendages short, flexuose, and bent upwards.—On -leaves of _Lycopsis arvensis_. Shere. October, 1865. (_Dr. Capron._) - - * * * * * - -=Chætomium murorum=, Corda. WALL BRISTLE-MOULD; gregarious, glaucous, -then blackish; perithecium globose, brown; hairs circinate, erect, -septate, pulverulent; spores oblong, yellowish. On plaster. Rare. (_M. -J. B._) - - ------------------------------------------------------------------------- - - - - - ADDENDA. - - ------- - -[The following species have been added to the British Flora since the - publication of the Appendix.] - -=Æcidium Parnassiæ=, Grav. PARNASSIA CLUSTER-CUPS; hypophyllous; spots -pallid; peridia in subrotund patches, irregularly disposed, -tawny-yellow, between urceolate and concave; the margin thick and nearly -entire; spores pallid. _Duby. Bot. Gall._ ii. p. 904.—On leaves of -_Parnassia palustris_, near Glasgow. (_Dr. Greville._) The original -specimen is in the Edinburgh Herbarium. - -=Æcidium Statices=, Desm. SEA-LAVENDER CLUSTER-CUPS; hypophyllous; spots -subrotund, or confluent and irregular, purple; peridia in subrotund -circinating clusters, sometimes irregularly disposed on the nerves and -petioles; urceolate; margin lacerated, white; spores orange. _Desm. -Exs._ No. 132. _Cooke, Exs._ No. 444.—On leaves and petioles of -_Statices_. June, July. Fleetwood, 1859 (_Rev. A. Bloxam_). Walney -Island, Lancashire, 1871 (_C. Bailey_). Near Basingstoke, 1871 (_R. S. -Hill_). Near Chichester, 1872 (_F. V. Paxton_). - -=Chætomium funicolum=, Cooke. TWINE BRISTLE-MOULD; perithecia scattered, -sub-ovate, black; hairs of the vertex very long, dichotomous or simple, -erect, slender, acute, black; sporidia lemon-shaped, dingy brown.—On -twine suspended in a vessel containing water at the British Museum. (_W. -Carruthers, F.R.S._) March, 1872. This species is most closely allied to -_C. elatum_, but much smaller and neater. It is wholly black, and -without the fibrous base of _C. elatum_. The hairs are more delicate, -not having half the diameter, and the sporidia are scarcely more than -half as long or broad. A species of _Polyactis_ afterwards made its -appearance on the same mycelium on some portion of the twine left behind -with a few immature perithecia. - - ------------------------------------------------------------------------- - - - - - EXPLANATION OF PLATES. - - ------- - - - Plate fig. - - I. 1. Goatsbeard with its cluster-cups (_Æcidium - Tragopogonis_). - - 〃 2. Fragment of same, slightly magnified. - - 〃 3. Section of cluster-cup, further magnified. - - 〃 4. Leaf of wood-anemone with its cluster-cups - (_Æcidium leucospermum_). - - 〃 5. Portion of same, slightly magnified. - - 〃 6. Anemone cluster-cups, further magnified. - - 〃 7. Leaf of Berberry with cluster-cups (_Æcidium - Berberidis_). - - 〃 8. Cluster of cups from the Berberry, as seen with a - lens. - - 〃 9. Cluster-cups of Berberry, magnified. - - 〃 10. Nettle-stem distorted by growth of cluster-cups - (_Æcidium Urticæ_). - - 〃 11. Nettle cluster-cups, magnified. - - II. 12. Leaf of Pilewort with groups of cluster-cups - (_Æcidium Ranunculacearum_). - - 〃 13. Group of cluster-cups from Pilewort, as seen with - a lens. - - 〃 14. Section of Pilewort cluster-cups, magnified. - - 〃 15. Bedstraw cluster-cups (_Æcidium Galii_) on the - Great Hedge Bedstraw. - - 〃 16. Tip of leaflet with cluster of cups, viewed - through a lens. - - 〃 17. Bedstraw cluster-cup from same, magnified. - - 〃 18. Leaflets of Mountain-ash with horn-shaped - cluster-cups (_Rœstelia cornuta_). - - 〃 19. Group of Mountain-ash cluster-cups, magnified. - - 〃 20. Pear-leaf with its cluster-cups (_Rœstelia - cancellata_). - - 〃 21. Cluster-cup from the same, magnified. - - 〃 22. Leaves and fruit of Hawthorn with lacerated - cluster-cups (_Rœstelia lacerata_). - - 〃 23. Elongated cells forming the walls of the - cluster-cups, × 250. - - 〃 24. Single cell, more highly magnified, with its - parallel striæ. - - 〃 25. Cluster-cups from fruit of Hawthorn, magnified. - - 〃 26. Section of same, further magnified. - - 〃 27. Fir-leaves bearing cluster-cups (_Peridermium - Pini_). - - 〃 28. Isolated cup of same, magnified. - - III. 29. Many-jointed fruit of Burnet chain-brand - (_Xenodochus carbonarius_), magnified. - - 〃 30. Leaflets of Burnet with rust on the lower, and - brand (_Aregma acuminatum_) on the upper - leaflets. - - 〃 31. Spores of Burnet rust (_Lecythea Poterii_) × 230. - - 〃 32. Fruit of Burnet brand (_Aregma acuminatum_). - - 〃 33. Leaf of Barren Strawberry with rust and brand - intermixed. - - 〃 34. Spores of Barren Strawberry rust × 230. - - 〃 35. Fruit of Strawberry brand (_Aregma obtusatum_) × - 300. - - 〃 36. Leaflet of Rose with its rust and brand - intermixed. - - 〃 37. Spores of Rose rust (_Lecythea Rosæ_) × 230. - - 〃 38. Fruit of Rose brand (_Aregma mucronatum_) × 300. - - 〃 39. Leaflet of Bramble, with its rust and brand - intermixed. - - 〃 40. Spores of Bramble rust (_Lecythea Ruborum_) × 230. - - 〃 41. Fruit of Bramble brand (_Aregma bulbosum_) × 300. - - 〃 42. Leaflet of Raspberry with its brand. - - 〃 43. Fruit of Raspberry brand (_Aregma gracile_) × 230. - - 〃 44. Cluster of fruits of Rose brand (_Aregma - mucronatum_) × 230. - - 〃 45. Fruit of Bramble brand (_Aregma bulbosum_) in - active germination, with sporidia at the tips of - the threads × 300. - - 〃 46. Fruit of Bramble brand (_Aregma bulbosum_) - ruptured, with inner cell escaping × 250 (_F. - Currey_). - - 〃 47. Portion of leaflet of Meadow-sweet with its brand. - - 〃 48. Spores of Meadow-sweet brand (_Triphragmium - ulmariæ_) × 300. - - 〃 49. Spore of Meadow-sweet brand (_Triphragmium - ulmariæ_) in germination, with sporidia borne on - the germ-tubes × 300 (_Tulasne_). - - 〃 50. Sprig of _Thesium humifusum_ bearing - Bastard-toadflax cluster-cups (_Æcidium - Thesii_). - - 〃 51. Portion of leaf of same, with cluster-cups, - enlarged. - - 〃 52. Leaflet of _Trientalis Europæa_ with its smut - (_Tuburcinia Trientalis_). - - 〃 53. Spores of the same × 320. - - 〃 54. Spores of Potato smut (_Tuburcinia scabies_) × - 320. (_Berkeley._) - - 〃 55. Leaflet of Alexanders (_Smyrnium olusatrum_) with - its brand. - - 〃 56. Spores of Alexanders brand (_Puccinia Smyrnii_) × - 320. - - IV. 57. Wheat-straw attacked by mildew (_Puccinia - graminis_). - - 〃 58. Cluster of spores of corn-mildew, magnified - (_Bauer_). - - 〃 59. Single spore of corn-mildew (_Puccinia graminis_) - × 300. - - 〃 60. Portion of blade of grass with coronated mildew - (_Puccinia coronata_). - - 〃 61. Portion of same enlarged, showing the pustules, or - sori. - - 〃 62. Spore of coronated mildew (_Puccinia coronata_) × - highly. - - 〃 63. Portion of leaf of Spear-thistle with its brand - (_Puccinia syngenesiarum_). - - 〃 64. Spores of Thistle brand (_Puccinia syngenesiarum_) - × 320. - - 〃 65. Leaf of Wood-anemone with brand (_Puccinia - anemones_). - - 〃 66. Spore of Anemone brand (_Puccinia anemones_) × - 320. - - 〃 67. Leaf of _Centaurea nigra_ with brand. - - 〃 68. Spores of Composite-brand (_Puccinia - compositarum_) × 320. - - 〃 69. Leaf of Mint with Mint brand (_Puccinia menthæ_). - - 〃 70. Spore of Mint brand (_Puccinia menthæ_) × 350. - - 〃 71. Portion of leaf of Earth-nut with brand (_Puccinia - umbelliferarum_). - - 〃 72. Spore of Earth-nut brand (_Puccinia - umbelliferarum_) × 320. - - 〃 73. Leaf of Ground-ivy with its brand (_Puccinia - Glechomatis_). - - 〃 74. Spore of Ground-ivy brand (_Puccinia Glechomatis_) - × 320. - - 〃 75. Pustule of brand surrounded by the ruptured - epidermis, magnified. - - 〃 76. Portion of leaf and stem of Goatsbeard with brand. - - 〃 77. Spores of the same × 320. - - 〃 78. Portion of leaf of Willow-herb with its brand - (_Puccinia pulverulenta_). - - 〃 79. Spores of Willow-herb brand (_Puccinia - pulverulenta_) × 320. - - 〃 80. Leaf of Pennywort with brand (_Puccinia - umbilici_). - - 〃 81. Spores of Pennywort-brand (_Puccinia umbilici_) × - 320. - - 〃 82. Portion of leaf of Dandelion with its brand. - - 〃 83. Spores of Variable-brand (_Puccinia variabilis_) × - 320. - - V. 84. Grain of Wheat infected with Fœtid smut - (_Tilletia caries_). - - 〃 85. Longitudinal section of the same. - - 〃 86. Spores of Fœtid smut (_Tilletia caries_) mixed - with delicate branching threads × 320. - - 〃 87. Spores of Fœtid smut in germination × highly. - - 〃 88. Sporidia of the first order borne on the - germinating tubes of the fœtid smut (_Tilletia - caries_) × highly. - - 〃 89. Sporidia of the first order, showing their - transverse connection, × highly. - - 〃 90. Sporidia of the first order, producing sporidia of - the second order, × highly. - - 〃 91. Sporidium of the second order in active - germination. - - 〃 92. Deformed flower-head of Goatsbeard infested with - smut (_Ustilago receptaculorum_). - - 〃 93. Floret removed, sprinkled with spores of the smut, - enlarged. - - 〃 94. Spores of Goatsbeard smut (_Ustilago - receptaculorum_) × 460. - - 〃 95. The same in active germination × 460 (_Tulasne_). - - 〃 96. Beaksedge (_Rhyncospora alba_) with its smut - (_Ustilago Montagnei_). - - 〃 97. Spores of _Ustilago Montagnei_ × 460. - - 〃 98. Ear of Barley infected with smut (_Ustilago - segetum_). - - 〃 99. Spores of Corn-smut (_Ustilago segetum_) × 460. - - 〃 100. Grass with its smut (_Ustilago hypodytes_). - - 〃 101. Spores of Grass-smut (_Ustilago hypodytes_). - - 〃 102. Flowers of Bladder-campion with anther smut - (_Ustilago antherarum_). - - 〃 103. Anther distorted by smut (_Ustilago antherarum_). - - 〃 104. Spores of Anther smut (_Ustilago antherarum_) × - 460. - - 〃 105. Portion of leaf of water grass with Elongated smut - (_Ustilago longissima_). - - 〃 106. Pustule of same, enlarged. - - 〃 107. Spores of Elongated smut (_Ustilago longissima_) × - very highly. - - 〃 108. Spores of Maize smut (_Ustilago maydis_) × 460. - - VI. 109. Sedge (_Carex recurva_) with Sedge smut (_Ustilago - urceolorum_). - - 〃 110. Single fruit covered with the smut. - - 〃 111. Spores of Sedge smut (_Ustilago urceolorum_) × - 460. - - 〃 112. Flower of _Polygonum persicaria_ distorted by - Utricle smut (_Ustilago utriculosa_). - - 〃 113. Section of the same (_Tulasne_). - - 〃 114. Inflorescence of _Polygonum hydropiper_ with - Utricle smut (_Ustilago utriculosa_). - - 〃 115. Section of infected flower of _Polygonum - hydropiper_. - - 〃 116. Spores of Utricle smut (_Ustilago utriculosa_) × - 460. - - 〃 117. Leaf of Cocksfoot, grass with smut (_Ustilago - Salveii_). - - 〃 118. Portion of leaf, showing pustules, × slightly. - - 〃 119. Spores of Cocksfoot smut (_Ustilago Salveii_) × - 320. - - 〃 120. Grass stem with Banded smut (_Ustilago grammica_). - - 〃 121. Portion of same, showing arrangement of the - pustules, × slightly. - - 〃 122. Spores of banded smut (_Ustilago grammica_) × 320. - - 〃 123. Inflorescence of Scabious with Floret smut - (_Ustilago flosculorum_). - - 〃 124. Floret occupied by the smut. - - 〃 125. Spores of Floret smut (_Ustilago flosculorum_) × - 320. - - 〃 126. Sedge (_Carex riparia_) attacked by Olive smut - (_Ustilago olivacea_). - - 〃 127. Spores of Olive smut (_Ustilago olivacea_) × 460. - - 〃 128. Reed stem with smut (_Ustilago typhoides_). - - 〃 129. Spores of Reed smut (_Ustilago typhoides_) × 320. - - 〃 130. Leaf of Periwinkle with its rust (_Trichobasis - vincæ_). - - 〃 131. Spores of Periwinkle rust (_Trichobasis vincæ_) × - 320. - - 〃 132. Spores of Periwinkle brand (_Puccinia vincæ_) × - 320. - - VII. 133. Leaf of Mercury with its rust (_Uredo confluens_). - - 〃 134. Spores of Mercury rust (_Uredo confluens_) × 320. - - 〃 135. Leaf of Enchanter’s Nightshade with its rust. - - 〃 136. Spores of Nightshade rust (_Uredo Circææ_) × 320. - - 〃 137. Leaf of Sorrel with Twin-faced rust (_Uredo - bifrons_). - - 〃 138. Pustule of Twin-faced rust seated on a coloured - spot × slightly. - - 〃 139. Spores of the same rust × 320. - - 〃 140. Leaf of Wheat with Corn rust (_Trichobasis - rubigo-vera_). - - 〃 141. Pustules of the same rust × slightly. - - 〃 142. Spores of Round corn rust × 320. - - 〃 143. Tuft of spores of Elongated corn rust - (_Trichobasis linearis_) magnified. - - 〃 144. Spores of Elongated corn rust (_Trichobasis - linearis_) × 320. - - 〃 145. Leaf of Groundsel with its rust (_Trichobasis - Senecionis_). - - 〃 146. Spores of Groundsel rust (_Trichobasis - Senecionis_) × 320. - - 〃 147. Wild Rose with Golden rust (_Uromyces Ulmariæ_). - - 〃 148. Spores of Golden rust × 320. - - 〃 149. Leaf of Vetch with Long-stemmed rust (_Uromyces - appendiculata_). - - 〃 150. Spores of the same × 460. - - 〃 151. Leaf of Common thistle with Sweet-smelling rust - (_Trichobasis suaveolens_). - - 〃 152. Spores of Sweet rust (_Trichobasis suaveolens_) × - 320. - - 〃 153. Spermogone of Sweet rust, from common thistle, × - highly (_De Bary_). - - 〃 154. Clover leaf with Short-stemmed rust (_Uromyces - apiculosa_). - - 〃 155. Spores of Short-stemmed rust × 320. - - 〃 156. Leaf of Pilewort with its rust (_Uromyces - Ficariæ_). - - 〃 157. Spores of Pilewort rust (_Uromyces Ficariæ_) × - 320. - - 〃 158. Portion of leaf of _Luzula_ with Oblong rust - (_Trichobasis oblongata_). - - 〃 159. Spores of Oblong rust (_Trichobasis oblongata_) × - 320. - - VIII. 160. Leaf of Sallow with its rust (_Lecythea - capræarum_). - - 〃 161. Spores of Sallow rust (_Lecythea capræarum_) × - 320. - - 〃 162. Bramble leaf with Ringed rust (_Lecythea gyrosa_). - - 〃 163. Pustule of Ringed rust (_Lecythea gyrosa_) × - slightly. - - 〃 164. Spores of Ringed rust (_Lecythea gyrosa_) × 320. - - 〃 165. Purging Flax with its rust (_Lecythea Lini_). - - 〃 166. Pustule of the same × slightly. - - 〃 167. Spores of Flax rust (_Lecythea Lini_) × 320. - - 〃 168. Leaf of Flukewort with its rust (_Trichobasis - hydrocotyles_). - - 〃 169. Spores of _Trichobasis hydrocotyles_ × 320. - - 〃 170. Portion of leaf of Sedge with its rust - (_Trichobasis caricina_). - - 〃 171. Spores of Sedge rust (_Trichobasis caricina_) × - 320. - - 〃 172. Whorl of leaves of Hedge Bedstraw with Bedstraw - brand (_Puccinia Galii_). - - 〃 173. Spores of Bedstraw brand (_Puccinia Galii_) × 320. - - 〃 174. Leaf of Tutsan with St. John’s-wort rust (_Uredo - hypericorum_). - - 〃 175. Spores of St John’s-wort rust (_Uredo - hypericorum_) × 320. - - 〃 176. Leaves of Cow-wheat with its rust (_Coleosporium - rhinanthacearum_). - - 〃 177. Spores of Cow-wheat rust (_Coleosporium - rhinanthacearum_) × 320. - - 〃 178. Portion of leaf of Sow-thistle with its rust - (_Coleosporium sonchi-arvensis_). - - 〃 179. Spores of Sow-thistle rust × highly (_De Bary_). - - 〃 180. Portion of Coltsfoot leaf with its rust - (_Coleosporium Tussilaginis_). - - 〃 181. Spores of Coltsfoot rust × highly. - - 〃 182. Group of spores of Coltsfoot rust _in situ_ × - highly (_Tulasne_). - - IX. 183. Leaf of Buttercup with Buttercup smut (_Polycystis - pompholygodes_). - - 〃 184. Fruit of Buttercup smut (_Polycystis - pompholygodes_) × 460. - - 〃 185. Violet leaf distorted by Violet smut (_Polycystis - Violæ_). - - 〃 186. Fruit of Violet smut (_Polycystis Violæ_) × 460. - - 〃 187. Portion of Rye-leaf with Rye smut (_Polycystis - parallela_). - - 〃 188. Fruit of Rye smut (_Polycystis parallela_) ×460. - - 〃 189. Dead Birch leaf with Birch wedge-rust (_Melampsora - betulina_). - - 〃 190. Winter spores of (_Melampsora betulina_) × 460. - - 〃 191. Portion of Sallow leaf with Willow wedge-rust - (_Melampsora salicina_). - - 〃 192. Winter spores of _Melampsora salicina_ × 460. - - 〃 193. Leaves of Spurge with Spurge wedge-rust - (_Melampsora Euphorbiæ_). - - 〃 194. Winter spores of _Melampsora Euphorbiæ_ × highly. - - 〃 195. Portion of Poplar-leaf with Poplar wedge-rust - (_Melampsora populina_). - - 〃 196. Winter spores of _Melampsora populina_ × 460. - - 〃 197. Winter spores of _Melampsora betulina_ in active - germination—_a_ sporidia × 466 (_Tulasne_). - - X. 198. Fruit of Shepherd’s-Purse with White rust - (_Cystopus candidus_). - - 〃 199. Portion of Cabbage-leaf with White rust (_Cystopus - candidus_). - - 〃 200. Conidia of White rust (_Cystopus candidus_) × 360. - - 〃 201. Portion of Goatsbeard-leaf with White rust - (_Cystopus cubicus_). - - 〃 202. Conidia of Goatsbeard white rust (_Cystopus - cubicus_) × 360. - - 〃 203. Portion of Mycelium producing the first of a chain - of conidia × 400. - - 〃 204. Mycelium of White rust with sucker-like processes - × 360. - - 〃 205. Mycelium of White rust with nascent oogonia × 360. - - 〃 206. Oogonium of Crucifer white rust (_Cystopus - candidus_) × 400 (_De Bary_). - - 〃 207. The same, further advanced, ruptured, with - zoospores, × 400. - - 〃 208. Free zoospores of White rust, with their ciliæ, × - 400 (_De Bary_). - - 〃 209. Resting zoospores in germination × 400 (_De - Bary_). - - 〃 210. Oogonium of Goatsbeard white rust (_Cystopus - cubicus_) × 400 (_De Bary_). - - 〃 211. Oogonium of Sandwort mould (_Peronospora - arenariæ_) × 400 (_De Bary_). - - 〃 212. Oogonium of Pea mould (_Peronospora viciæ_) × 400 - (_De Bary_). - - 〃 213. Oogonium of Veronica mould (_Peronospora grisea_) - × 400 (_De Bary_). - - 〃 214. Oogonium of Spinach mould (_Peronospora effusa_) × - 400 (_De Bary_). - - 〃 215. Leaf of Goosefoot with mould (_Peronospora - effusa_). - - XI. 216. Conceptacle of Hop mildew (_Sphærotheca - castagnei_) × 80. - - 〃 217. Conceptacle of Rose blight (_Sphærotheca pannosa_) - × 80. - - 〃 218. Sporangium of _Sphærotheca pannosa_ × highly. - - 〃 219. Conceptacle of Hazel blight (_Phyllactinia - guttata_) × 80. - - 〃 220. Sporangium of _Phyllactinia guttata_ × highly. - - 〃 221. Portion of leaf of Willow with Willow blight - (_Uncinula adunca_). - - 〃 222. Conceptacle of Willow blight (_Uncinula adunca_) × - 80. - - 〃 223. Tip of one of the appendages × highly. - - 〃 224. Sporangium of Willow blight (_Uncinula adunca_) × - highly. - - 〃 225. Conceptacle of Maple blight (_Uncinula bicornis_) - × 80. - - 〃 226. Tip of one of the appendages of _Uncinula - bicornis_ × highly. - - 〃 227. Furcate tip of one of the appendages of the Maple - blight (_Uncinula bicornis_) × highly. - - 〃 228. Sporangium of _Uncinula bicornis_ × highly. - - 〃 229. Leaf of Berberry with Berberry blight - (_Microsphæria Berberidis_). - - 〃 230. Conceptacle of Berberry blight × 80. - - 〃 231. Tip of one of the appendages of Berberry blight - (_Microsphæria Berberidis_) × highly. - - 〃 232. Sporangium of Berberry blight × highly. - - 〃 233. Tip of appendage of a continental species of - blight (_Microsphæria Ehrenbergii_) × highly - (_Léveillé_). - - 〃 234. Tip of appendage of Alder blight (_Microsphæria - penicillata_) × highly. - - 〃 235. Portion of Grass leaf with blight (_Oidium - monilioides_). - - 〃 236. Tuft of conidia of _Oidium monilioides_ × 120. - - 〃 237. Leaflet of Garden Pea with Pea blight (_Erysiphe - Martii_). - - 〃 238. Conceptacle of Pea blight (_Erysiphe Martii_) × - 80. - - 〃 239. Sporangium of _Erysiphe Martii_ × highly. - - 〃 240. Conceptacle of Buttercup blight (_Erysiphe - communis_) × 80. - - 〃 241. Sporangium of _Erysiphe communis_ × highly. - - 〃 242. Sucker from the mycelium of _Erysiphe communis_, - magnified. - - XII. 243. Conceptacle of Mealy Guelder-rose blight - (_Microsphæria Hedwigii_) × 80. - - 〃 244. Sporangium of same, containing spores, × highly. - - 〃 245. Conceptacle of Cornel blight (_Erysiphe tortilis_) - × 80. - - 〃 246. Sporangium of same, containing spores, × highly. - - 〃 247. Tip of appendage of _Microsphæria Hedwigii_ × - highly. - - 〃 248. Sporangium of Mugwort blight (_Erysiphe Linkii_), - containing spores, × highly. - - 〃 249. Conceptacle of Mugwort blight (_Erysiphe Linkii_) - × 80. - - 〃 250. Sporangium and spores of Plantain blight - (_Erysiphe lamprocarpa_) × highly. - - 〃 251. Conceptacle of Plantain blight (_Erysiphe - lamprocarpa_) × 80. - - 〃 252. Conceptacle of Paper bristle-mould (_Chætomium - chartarum_) magnified. - - 〃 253. Sporidium of the same, further magnified. - - 〃 254. Conceptacle of Paper mildew (_Ascotricha - chartarum_) magnified (_Berkeley_). - - 〃 255. Portion of thread of same with conidia, further - magnified (_Berkeley_). - - 〃 256. Sporangium of same, containing spores - (_Berkeley_). - - 〃 257. Piece of straw with Bristle mould (_Chætomium - elatum_). - - 〃 258. Conceptacle of same, slightly magnified. - - 〃 259. Section of same, further magnified. - - 〃 260. Dead leaf over-run with Herbarium mildew - (_Eurotium herbariorum_). - - 〃 261. Conceptacles of the same, seated on their - mycelium, magnified. - - XIII. 262. Fertile thread of Turnip mould (_Peronospora - parasitica_). - - 〃 263. Fertile thread of Onion mould (_Peronospora - Schleideniana_). - - XIV. 264. Fertile thread of Potato mould (_Peronospora - infestans_). - - 〃 265. Fertile thread of Lettuce mould (_Peronospora - gangliformis_). - - XV. 266. Fertile thread of Pea mould (_Peronospora Viciæ_). - - 〃 267. Fertile thread of Anemone mould (_Peronospora - curta_). - - XVI. 268. Fertile thread of Sandwort mould (_Peronospora - arenariæ_). - - 〃 269. Fertile thread of Dock mould (_Peronospora - obliqua_) × 320. - - ------------------------------------------------------------------------- - - - - - INDEX. - - - PAGE - - Acrospores, 141 - Æcidiacei, 189 - _Æcidiolum exanthematum_, 22 - _Æcidium_, 5 - —— (Descriptions), 190 - —— _Euphorbiæ_, 11 - —— _Galii_, 15 - —— _leucospermum_, 11 - —— _quadrifidum_, 11 - —— _Ranunculacearum_, 12 - —— _Saniculæ_, 15 - —— _Thesii_, 15 - —— _Tragopogonis_, 5 - Alternation of Generations, 38 - Anemone brand, 60 - —— cluster-cups, 10 - Anther smut, 85 - Antheridia, 129 - Appendages or fulcra, 165 - APPENDIX, 189 - _Aregma bulbosum_, 69 - —— (Descriptions), 195 - —— _gracilis_, 71 - —— _mucronatum_, 34 - —— _obtusatum_, 73 - _Artotrogus_, 151 - Asci, 35 - _Ascomyces Rumicis_, 161 - _Ascotricha chartarum_, 175 - —— (Descriptions), 221 - - Bean rust, 104 - Bedstraw cluster-cups, 15 - Beet rust, 104 - Berberry cluster-cups, 16 - Berberry mildew, 170 - Birch rust, 118 - —— wedge-rust, 118 - Blackberry brand, 68 - Bladder brand, 86 - Blight, Berberry, 170 - —— Burdock, 174 - —— Crowfoot, 173 - —— Dogwood, 174 - —— Gooseberry, 171 - —— Guelder-rose, 171 - —— Hazel, 168 - —— Hop, 169 - —— Indian Cotton, 177 - —— Maple, 167 - —— Mealy Guelder-rose, 172 - —— Mugwort, 174 - —— Pea, 173 - —— Plantain, 174 - —— Rose, 166 - —— Salsify, 174 - —— Willow, 169 - _Boletus cyanescens_, 106 - _Botrytis devastatrix_, 153 - —— _fallax_, 153 - —— _infestans_, 153 - Bramble brand, 68 - Brand, Anemone, 60 - —— Bladder, 86 - —— Bramble, 68 - —— Burnet chain, 73 - —— Centaury, 63 - —— Complex, 67 - —— Dust, 76 - —— Earth-nut, 64 - —— Goatsbeard, 65 - —— Ground-ivy, 59 - —— Meadow-sweet, 67 - —— Mint, 58 - —— Pepper, 86 - —— Periwinkle, 103 - —— Raspberry, 71 - —— Sanicle, 64 - —— Strawberry, 72 - —— Thistle, 62 - Bristle-moulds, 175 - Buckthorn cluster-cups, 16 - Bunt, 86 - Bunt, germination, 87 - Burdock blight, 174 - Burnet chain-brand, 73 - Butter-bur rust, 122 - Buttercup blight, 173 - —— cluster-cups, 12 - - Cabbage rust, 136 - Campanula rust, 123 - Centaury brand, 63 - _Chætomium_ (Descriptions), 221 - —— _elatum_, 175 - Classification, 189 - Clover rust, 116 - CLUSTER-CUPS, 2 - Cluster-cup, Anemone, 10 - —— Bedstraw, 15 - —— Berberry, 16 - —— Buckthorn, 16 - —— Buttercup, 12 - —— Fir-tree, 20 - —— Goatsbeard, 3 - —— Hawthorn, 17 - —— Houseleek, 21 - —— Mountain-Ash, 19 - —— Nettle, 14 - —— Pear-tree, 18 - —— Sanicle, 14 - —— Spurge, 11 - —— Violet, 13 - Cocksfoot smut, 83 - _Coleosporium_, 119 - —— _Campanulæ_, 122 - —— (Descriptions), 212 - —— _petasites_, 122 - —— _tussilaginis_, 120 - _Coleosporium sonchi-arvensis_, 122 - —— _Rhinanthacearum_, 122 - Collecting fungi, 179 - Coltsfoot rust, 120 - COMPLEX BRANDS, 67 - Complex smuts, 90 - Composite rust, 105 - Conceptacles, 165 - Conidia, 126 - _Coniomycetes_, 5 - Conjurer of Chalgrave’s fern, 61 - Corn mildew, 48 - —— mildew, germination, 55 - —— rust, 49, 52, 95 - —— smut, 79 - Cornel blight, 174 - Coronated mildew, 56 - Cotton blight in India, 177 - Cow-parsnip rust, 105 - Cow-wheat rust, 122 - Crowfoot blight, 173 - Crucifer white rust, 136 - _Cryptosporium Neesii_, 35 - _Cystopus_, 124, 136 - —— _candidus_, 136 - —— _cubicus_, 136 - —— (Descriptions), 214 - —— _Lepigoni_, 136 - - Dandelion parasites, 61 - De Bary’s experiments, 129 - Descriptions, 189 - DI-MORPHISM, 33 - Diseases of wheat, 85 - Dock mould, 160 - Dogwood blight, 174 - _Dothidea ribis_, 36 - Dust-brand, 76 - - Earth-nut brand, 64 - Elongated corn rust, 95 - —— smut, 84 - Enchanter’s Nightshade rust, 112 - _Endophyllum_, 20 - —— (Descriptions), 194 - Endospore, 40 - Epispore, 40 - _Erineum acerinum_, 170 - _Erysiphe communis_, 173 - —— (Descriptions), 220 - —— _lamprocarpa_, 174 - —— _Linkii_, 174 - —— _Martii_, 173 - —— _Montagnei_, 174 - —— _tortilis_, 174 - _Eurotium_ (Descriptions), 222 - —— _herbariorum_, 177 - Examining fungi, 183 - - Fern rust, 112 - Fungi, species of, 45 - - Generations, alternation of, 38 - Genus and species, 58 - Germination of mildew, 55 - —— of pea rust, 40 - Goatsbeard cluster-cups, 3 - —— smut, 82 - —— white rust, 136 - Goat-willow rust, 116 - Golden-rose rust, 113 - Gonosphere, 130 - Gooseberry blight, 171 - Ground-ivy brand, 59 - Groundsel rust, 97 - Guelder-rose blight, 171 - _Gymnosporangium_ (Descriptions), 201 - - Hawthorn cluster-cups, 17 - Hazel blight, 168 - Herbarium mould, 177 - —— of fungi, 182 - Hop disease, 167 - Hyphomycetes, 139 - - Inoculation, 9 - Iris rust, 115 - - _Lecythea_, 107 - —— _capræarum_, 117 - —— (Descriptions), 206 - —— _Lini_, 108 - —— _longicapsula_, 118 - —— _Rosæ_, 34, 107 - Lettuce mould, 156 - Line-like rust, 95 - Long-stemmed rust, 114 - Luzula rust, 104 - - Maple blight, 169 - Meadow-saffron smut, 92 - Meadow-sweet brand, 67 - Mealy Guelder-rose blight, 172 - _Melampsora betulina_, 118 - —— (Descriptions), 213 - —— _salicina_, 117 - Mercury rust, 110 - Microscopic examination, 183 - —— fungi collecting, 179 - Microscopic preserving, 182 - _Microsphæria Berberidis_, 170 - —— (Descriptions), 219 - —— _Ehrenbergii_, 171 - —— _Hedwigii_, 172 - Mildew and brand, 45 - —— what is it?, 46 - Mint brand, 58 - —— rust, 102 - Monthly calendar of fungi, 180 - Moulds, 138 - Mould, Dock, 160 - —— Lettuce, 156 - —— Onion, 155 - —— Parsnip, 157 - —— Potato, 144 - —— Rose, 159 - —— Spinach, 158 - —— Tare, 156 - Mountain-ash cluster-cups, 19 - Mounting fungi, 184 - Mugwort blight, 174 - Mycelium, 23 - - Nettle cluster-cups, 14 - Nightshade rust, 112 - Number of species, 45 - - Oak-leaf rust, 111 - _Oidium_, 34, 162 - —— _leucoconium_, 167 - —— _monilioides_, 162 - —— _Tuckeri_, 164 - Onion mould, 155 - Oogonia, 129 - Oospores, 131 - Origin of mildew, 47 - - Parsnip mould, 157 - Pea blight, 173 - Pear tree cluster-cups, 18 - Pea and bean rust, 114 - Pearust, germination of, 40 - Pennywort rust, 100 - _Peridermium_, 20 - —— (Descriptions), 189 - _Peridium_, 4 - _Perithecium_, 35 - Periwinkle brand, 103 - —— rust, 103 - Persicaria rust, 104 - _Peronospora_, 138 - —— (Descriptions), 215 - —— _destructor_, 156 - —— _effusa_, 159 - —— _gangliformis_, 156 - —— _infestans_, 153 - —— _macrospora_, 158 - —— _nivea_, 157 - —— _obliqua_, 160 - —— _Schleideniana_, 155 - —— _sparsa_, 159 - —— _Trifoliorum_, 157 - —— _Umbelliferarum_, 158 - —— _Viciæ_, 156 - Pepper brand, 86 - _Phragmidium_, 71 - _Phyllactinia_ (Descriptions), 218 - —— _guttata_, 168 - Pilewort rust, 115 - _Podisoma_ (Descriptions), 201 - _Polycystis_, 91 - —— (Descriptions), 211 - —— _pompholygodes_, 91 - —— _Violæ_, 92 - Potato disease, 144 - —— mould, 142, 144 - —— smut, 93 - Preserving fungi, 182 - _Puccinia_ (Descriptions), 196 - —— _Anemones_, 60 - —— _Compositarum_, 63 - —— _coronata_, 57 - —— _glechomatis_, 59 - —— _graminis_, 25 - —— _Menthæ_, 58 - —— _Rosæ_, 34 - —— _Saniculæ_, 64 - —— _Syngenesiarum_, 62 - —— _Umbelliferarum_, 64 - —— _variabilis_, 62 - —— _vincæ_, 103 - Purslane white rust, 137 - - Raspberry brand, 71 - Reed smut, 83 - _Rœstelia_ (Descriptions), 189 - —— _cancellata_, 19 - —— _cornuta_, 19 - —— _lacerata_, 19 - Rose blight, 166 - —— mould, 107 - —— rust, 159 - _Rusts_, 95, 110 - Rust, Bean, 104 - —— Beet, 104 - —— Birch, 118 - —— Butter-bur, 122 - —— Cabbage, 124 - —— Campanula, 123 - —— Clover, 116 - —— Coltsfoot, 120 - —— Composite, 105 - —— Corn, 49, 95 - —— Cow-parsnip, 105 - —— Cow-wheat, 122 - —— Fern, 112 - —— Flax, 109 - —— Goatsbeard, 136 - —— Goat-willow, 116 - —— Golden-rose, 113 - —— Grass of Parnassus, 106 - —— Groundsel, 97 - —— Iris, 115 - —— Long-stemmed, 114 - —— Luzula, 104 - —— Mercury, 110 - —— Mint, 102 - —— Nightshade, 112 - —— Oak-leaf, 111 - —— Pea and Bean, 114 - —— Pennywort, 100 - —— Periwinkle, 103 - —— Persicaria, 104 - —— Pilewort, 115 - —— Rose, 107 - —— St.-John’s-wort, 113 - —— Sandspurry, 136 - —— Sedge, 104 - —— Sorrel, 111 - —— Sow-thistle, 122 - —— Stinking, 87 - —— Sweet-smelling, 99 - —— Thistle, 99 - —— Twin-faced, 111 - —— Umbellifer, 105 - —— Violet, 102 - Rye smut, 92 - - Sandspurry white rust, 136 - Sanicle brand, 64 - —— cluster-cups, 14 - Sedge rust, 104 - —— smut, 84 - Smuts, 76 - Smut, Anther, 85 - —— Cocksfoot, 83 - —— Complex, 90 - —— Corn, 79 - —— Crowfoot, 91 - —— Elongated, 84 - —— Goatsbeard, 82 - —— Grass, 79 - —— Maize, 79 - —— Meadow-saffron, 92 - —— Potato, 93 - —— Reed, 83 - —— Rye, 92 - —— Sedge, 84 - —— Trientalis, 93 - —— Violet, 92 - St.-John’s-wort rust, 113 - Sow-thistle rust, 122 - Specific names, 57 - Spermatia, 24 - SPERMOGONES, 22, 98 - _Sphærotheca_ (Descriptions), 218 - —— _Castagnei_, 167 - —— _pannosa_, 167 - Spinach mould, 158 - Sporangium, 165 - Sporidia, 38 - Spurge cluster-cups, 11 - Sterigmata, 24 - Stinking rust, 87 - Strawberry brand, 72 - Stylospores, 38, 42 - Suckers, 125, 141 - SUGGESTIONS, 179 - Sweet-smelling rust, 99 - - Tare mould, 156 - Thistle brand, 62 - Thistle white rust, 137 - _Tilletia caries_, 87 - —— (Descriptions), 202 - _Trichobasis Betæ_, 104 - —— _caricina_, 104 - —— _Cichoracearum_, 105 - —— (Descriptions), 207 - —— _Fabæ_, 104 - —— _hydrocotyles_, 100 - —— _Labiatarum_, 102 - —— _linearis_, 95 - —— _oblongata_, 105 - —— _Parnassiæ_, 106 - —— _Petroselini_, 105 - —— _Polygonorum_, 104 - —— _rubigo-vera_, 49, 95 - —— _Senecionis_, 97 - —— _suaveolens_, 99 - —— _Umbellatarum_, 105 - —— _Violarum_, 102 - Trientalis smut, 93 - _Triphragmium_ (Descriptions), 196 - —— _Ulmariæ_, 67 - _Tuburcinia_, 93 - —— (Descriptions), 212 - Tulasne on Fungi, 35 - Twin-faced rust, 111 - - _Uncinula adunca_, 169 - —— _bicornis_, 169 - —— (Descriptions), 218 - Uredines, 33 - _Uredo Betulina_, 118 - —— _bifrons_, 111 - —— _Circææ_, 112 - —— _confluens_, 110 - —— (Descriptions), 204 - —— _Filicum_, 112 - —— _hydrocotyles_, 101 - —— _Hypericorum_, 113 - —— _Parnassiæ_, 106 - —— _Quercus_, 111 - —— _Rosæ_, 33 - _Urocystis_, 91 - _Uromyces apiculata_, 116 - —— _appendiculata_, 40, 114 - —— (Descriptions), 210 - —— _Ficariæ_, 115 - —— _Ulmariæ_, 114 - _Ustilago antherarum_, 85 - —— (Descriptions), 202 - —— _longissima_, 84 - —— _maydis_, 79 - —— _olivacea_, 84 - —— _receptaculorum_, 83 - —— _Salveii_, 84 - —— _segetum_, 79 - —— _typhoides_, 79, 83 - - _Valsa suffusa_, 35 - Vine disease, 164 - Violet cluster-cups, 13 - Violet smut, 92 - - Wedge-rust, Birch, 118 - —— Willow, 117 - Wheat diseases, 85 - —— mildew, 53 - White mildews or blights, 162 - _White rusts_, 124 - White rust, Cabbage, 129, 136 - —— Crucifer, 136 - —— Goatsbeard, 136 - —— Purslane, 137 - —— Sandspurry, 136 - Willow blight, 169 - —— wedge-rust, 117 - - _Xenodochus carbonarius_, 73 - —— (Descriptions), 195 - - Zoospores, 126 - - - -------------------------------------------------- - - WYMAN AND SONS, PRINTERS, GREAT QUEEN STREET, LONDON, W.C. - - ------------------------------------------------------------------------- - - - - - ● Transcriber’s Notes: - ○ A link to the Index was added to the Table of Contents. - ○ The Table of Contents entry for the first Appendix has no - identifier. Clicking on the page number will take you to Appendix - A. - ○ The Table of Contents references Appendix II. This is should have - been a reference Appendix B. Clicking on the page number for - Appendix II will take you to Appendix B. - ○ The image of SPERMOGONES (Fig 1.) on page 25 has been rotated to - make the letter identifications more legible. - ○ On page 40 there is a reference to fig. 150, but nothing in that - figure is labeled 150. - ○ On page 56, in the footnote, there is a reference to fig. 45 on - Plate II. This was corrected to Plate III. - ○ On page 67 there is a reference to fig. 47 on Plate II. This was - corrected to Plate III. - ○ On page 69 there are references to figs. 47 and 41 on Plate II. - This was corrected to Plate III. - ○ On page 79 there is a reference to figs. 123—125 on Plate IV. This - was corrected to Plate VI. - ○ On page 216 there is a reference to fig. 268 on Plate VII. This - was corrected to Plate XVI. - ○ Missing or obscured punctuation was silently corrected. - ○ Typographical errors were silently corrected. - ○ Inconsistent spelling and hyphenation were made consistent only - when a predominant form was found in this book. - ○ Text that was in italics is enclosed by underscores (_italics_); - text that was bold by “equal” signs (=bold=). - - - - - - - -End of the Project Gutenberg EBook of Rust, Smut, Mildew, & Mold, by -Mordecai Cubitt Cooke - -*** END OF THIS PROJECT GUTENBERG EBOOK RUST, SMUT, MILDEW, & MOLD *** - -***** This file should be named 63416-0.txt or 63416-0.zip ***** -This and all associated files of various formats will be found in: - http://www.gutenberg.org/6/3/4/1/63416/ - -Produced by deaurider, Barry Abrahamsen, and the Online -Distributed Proofreading Team at https://www.pgdp.net (This -file was produced from images generously made available -by The Internet Archive) - -Updated editions will replace the previous one--the old editions will -be renamed. - -Creating the works from print editions not protected by U.S. copyright -law 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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