diff options
Diffstat (limited to '32018.txt')
| -rw-r--r-- | 32018.txt | 1545 |
1 files changed, 1545 insertions, 0 deletions
diff --git a/32018.txt b/32018.txt new file mode 100644 index 0000000..04dd43d --- /dev/null +++ b/32018.txt @@ -0,0 +1,1545 @@ +The Project Gutenberg EBook of Jaw Musculature of the Mourning and +White-winged Doves, by Robert L. Merz + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + + +Title: Jaw Musculature of the Mourning and White-winged Doves + +Author: Robert L. Merz + +Release Date: April 17, 2010 [EBook #32018] + +Language: English + +Character set encoding: ASCII + +*** START OF THIS PROJECT GUTENBERG EBOOK JAW MUSCULATURE--DOVES *** + + + + +Produced by Chris Curnow, Joseph Cooper, Diane Monico, and +the Online Distributed Proofreading Team at +https://www.pgdp.net + + + + + + + + + + + +UNIVERSITY OF KANSAS PUBLICATIONS +MUSEUM OF NATURAL HISTORY + +Volume 12, No. 12, pp. 521-551, 22 figs. +October 25, 1963 + + +Jaw Musculature +Of the Mourning and White-winged Doves + + +BY + +ROBERT L. MERZ + + +UNIVERSITY OF KANSAS +LAWRENCE +1963 + + + + +UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY + +Editors: E. Raymond Hall, Chairman, Henry S. Fitch, +Theodore H. Eaton, Jr. + +Volume 12, No. 12, pp. 521-551, 22 figs. +Published October 25, 1963 + + +UNIVERSITY OF KANSAS +Lawrence, Kansas + + +PRINTED BY +JEAN M. NEIBARGER, STATE PRINTER +TOPEKA, KANSAS +1963 + +29-7865 + + + + +Jaw Musculature +Of the Mourning and White-winged Doves + +BY + +ROBERT L. MERZ + + +For some time many investigators have thought that the genus _Zenaida_, +which includes the White-winged and Zenaida doves, and the genus +_Zenaidura_, which includes the Mourning, Eared, and Socorro doves +(Peters, 1937:83-88), are closely related, perhaps more closely than is +indicated by separating the several species into two genera. It is the +purpose of this paper to report investigations on the musculature of +the jaw of doves with the hope that, together with the results of other +studies, the relationships of the genera _Zenaida_ and _Zenaidura_ can +be elucidated. + + +METHODS AND MATERIALS + +In order to determine in each species the normal pattern of musculature +of the jaws, heads of 13 specimens of doves were dissected (all +material is in the Museum of Natural History of The University of +Kansas): White-winged Doves (_Zenaida asiatica_), 40323, 40324, 40328, +40392, 40393; Zenaida Doves (_Z. aurita_), 40399, 40400; Mourning Doves +(_Zenaidura macroura_), 40326, 40394, 40395, 40396, 40397, 40398. + +Thirty-seven skulls from the collection of the Museum of Natural +History of The University of Kansas and two skulls from the United +States National Museum were measured. The measurements are on file in +the Library of The University of Kansas in a dissertation deposited +there by me in 1963 in partial fulfillment of requirements for the +degree of Master of Arts in Zoology. Specimens used were: White-winged +Doves, KU 19141, 19142, 19143, 19144, 19145, 19146, 19147, 23138, +23139, 24337, 24339, 24341, 23592, 23593, 24340, 31025, 31276; Mourning +Doves, KU 14018, 14781, 15347, 15533, 15547, 15550, 15662, 15778, +15872, 16466, 17782, 17786, 17788, 17795, 19153, 19242, 20321, 21669, +22394, 22715; Eared Doves (_Zenaidura auriculata_), USNM 227496, +318381. Additionally, the skulls of the Zenaida Doves mentioned above +were measured. All measurements were made with a dial caliper and read +to tenths of a millimeter. + + +ACKNOWLEDGMENTS + +My appreciation is extended to Professor Richard F. Johnston, who +advised me during the course of this study, and to Professors A. Byron +Leonard and Theodore H. Eaton for critically reading the manuscript. + +I would like also to acknowledge the assistance of Dr. Robert M. Mengel +and Mr. Jon C. Barlow for suggestions on procedure, and Mr. William C. +Stanley, who contributed specimens of Mourning Doves for study. Mr. +Thomas H. Swearingen offered considerable advice on production of +drawings and Professor E. Raymond Hall suggested the proper layout of +the same and gave editorial assistance otherwise, as also did Professor +Johnston. + + +MYOLOGY + +The jaw musculature of doves is not an imposing system. The eating +habits impose no considerable stress on the muscles; the mandibles are +not used for crushing seeds, spearing, drilling, gaping, or probing as +are the mandibles of many other kinds of birds. Doves use their +mandibles to procure loose seeds and grains, which constitute the major +part of their diet (Leopold, 1943; Kiel and Harris, 1956: 377; Knappen, +1938; Jackson, 1941), and to gather twigs for construction of nests. +Both activities require but limited gripping action of mandibles. The +crushing habit of a bird such as the Hawfinch (_Coccothraustes +coccothraustes_), on the other hand, involves extremely powerful +gripping (see, for example, Sims, 1955); the contrast is apparent in +the development of the jaw musculature in the two types. Consequently, +it is not surprising to find a relatively weak muscle mass in the jaw +of doves, and because the musculature is weak there are few pronounced +osseous fossae, cristae and tubercles. As a result, the bones, in +addition to being small in absolute size, are relatively weaker when +compared to skulls of birds having more distinctive feeding habits +which require more powerful musculature. + +The jaw muscles of the species dissected for this study are, in gross +form, nearly identical from one species to another. Thus, a description +of the pertinent myology of each species is unnecessary; one basic +description is hereby furnished, with remarks on the variability +observed between the species. + +The terminology adopted by me for the jaw musculature is in boldfaced +italic type. Synonyms are in italic type and are the names most often +used by several other writers. + + ~_M. pterygoideus ventralis:_~ part of Mm. pterygoidei, Gadow, + 1891:323-325, table 26, figs. 1, 2, 3 and 4, and table 27, + fig. 3--part of M. pterygoideus internus, Shufeldt, 1890:20, + figs. 3, 5, 6, 7 and 11--part of M. adductor mandibulae + internus, Edgeworth, 1935:58, figs. 605c and 607--part of M. + pterygoideus anterior, Adams, 1919:101, pl. 8, figs. 2 and 3. + + ~_M. pterygoideus dorsalis:_~ part of Mm. pterygoidei, + Gadow, 1891:323-325, table 26, fig. 7 and table 27, figs. 1 + and 3--part of M. pterygoideus internus, Shufeldt, + 1890:20--part of M. adductor mandibulae internus, Edgeworth, + 1935:58, fig. 605c--? part of M. pterygoideus anterior, + Adams, 1919:101, pl. 8, figs. 2 and 3. + + ~_M. adductor mandibulae externus:_~ _a_) ~_pars + superficialis:_~ parts 1 and 2 of M. temporalis, Gadow, + 1891:320-321--part of M. temporal, Shufeldt, 1890:16, + figs. 5 and 7--part of M. adductor mandibulae externus, + Edgeworth, 1935:58-60--M. capiti-mandibularis medius and + profundus, Adams, 1919:101, pl. 8, fig. 1. + + _b_) ~_pars medialis:_~ ? parts 1, 2 and 3 of M. temporalis, + Gadow, 1891:320-322--part of M. masseter and ? part of M. + temporal, Shufeldt, 1890:16-18, figs. 5, 6, 7 and 11--part + of M. adductor mandibulae externus, Edgeworth, + 1935:58-60--M. capiti-mandibularis superficialis, first + part, Adams, 1919:100-101, pl. 8, fig. 1. + + _c_) ~_pars profundus:_~ part 2 of M. temporalis, Gadow, + 1891:321, table 27, fig. 2--part of M. temporal and ? part + of M. masseter, Shufeldt, 1890:16-18--part of M. adductor + mandibulae externus, Edgeworth, 1935:58-60--? part of M. + capiti-mandibularis medius and all of pars superficialis, + second part, Adams, 1919:100-101. + + ~_M. pseudotemporalis profundus:_~ M. quadrato-maxillaris, + Gadow, 1891:322-323--M. pterygoideus externus, Shufeldt, + 1890:20-21, figs. 3, 5 and 11--part of M. adductor mandibulae + medius, Edgeworth, 1935:58-59--? part of M. pterygoideus + posterior, Adams, 1919:101, pl. 8, figs. 2 and 3. + + ~_M. protractor pterygoidei:_~ part 4b of M. temporalis, + Gadow, 1891: 322-323, table 27, fig. 4--part of M. + entotympanious, Shufeldt, 1890:19-20, figs. 3 and 11--part + of M. spheno-pterygo-quadratus, Edgeworth, 1935:57. + + ~_M. depressor mandibulae:_~ M. digastricus s. depressor + mandibulae, Gadow, 1891:318-319--M. biventer maxillae, + Shufeldt, 1890:18-19, figs. 3, 4, 5, 6, 7 and 11. + + ~_M. pseudotemporalis superficialis:_~ M. spheno-maxillaris, + Gadow, 1891:323--part of M. temporal, Shufeldt, 1890:16--part + of M. pseudotemporalis, Hofer, 1950:468-477--part of M. + adductor mandibulae medius, Edgeworth, 1935:277. + + ~_M. adductor mandibulae posterior:_~ ? part of M. temporal, + Shufeldt, 1890:16--part of M. adductor mandibulae medius, + Edgeworth, 1935:58-59--? part of M. pterygoideus posterior, + Adams, 1919:101, pl. 8, figs. 2 and 3. + + ~_M. protractor quadrati:_~ part 4a of M. temporalis, Gadow, + 1891:322-323, table 27, fig. 4--part of M. entotympanicus, + Shufeldt, 1890:19-20, figs. 3 and 11--part of M. + spheno-pterygo-quadratus, Edgeworth, 1935:57. + +The terminology adopted by me is that of Lakjar (1926) except that the +divisions of _M. depressor mandibulae_ are designated by the Latinized +equivalents of the names used by Rooth (1953:261-262). + +~_M. pterygoideus ventralis lateralis._~--The origin is fleshy and by +aponeurosis on the ventral side of the palatine anterior to the +palatine fossa. The insertion is fleshy on the ventromedial surface of +the lower mandible and continues along the anteromedial surface of the +internal angular process to its distal tip. A few fibers leave _pars +lateralis_ and insert on an aponeurosis which receives also all the +fibers of _M. pterygoideus dorsalis lateralis_. The latter fact may +have prompted Rooth (1953:257) to make the statement that the fibers +originating on the dorsal part of the palatine inserted more laterally +than those originating on the ventral side. Rooth worked with _Columba +palumbus_, the Woodpigeon, and his description concerned _M. adductor +mandibulae internus pterygoideus_, which is composed of _Mm. +pterygoideus ventralis et dorsalis_ of Lakjar (1926). His assertion +that ventral fibers, that is to say, fibers arising on the ventral +surface of the palatine, insert medially does not appear to be +completely true for doves. + +Aponeuroses cover most of the lower surface of the muscle and one or +two nerves extend into the substance of the muscle. The nerves run from +the anterior edge of _M. pterygoideus dorsalis medialis_ and farther +posteriorly from a separation in the muscle. + +~_M. pterygoideus ventralis medialis._~--The origin is by aponeurosis +from the ventral surface of the palatine and fleshy from the palatine +fossa. The aponeurosis is the same that gives origin to the fibers of +_pars lateralis_. Part of the aponeurosis becomes tendonlike in the +middle of _M. pterygoideus ventralis_ and separates its two divisions. +The insertion is fleshy on the lower one-third of the anterior surface +of the internal angular process of the lower mandible, and by two +tendons on the distal tip of that process. Many of the fibers of _pars +medialis_ insert on the tendons. The fibers at their insertion are not +distinctly separate from those of _pars lateralis_ and there is +considerable mingling of the fibers. Consequently, the medial part of +_M. pterygoideus ventralis_ cannot be removed as a part distinct from +the lateral part (figs. 1, 4, 10, 21 and 22). + +Ordinarily _M. pterygoideus ventralis_ does not cross the ventral edge +of the lower mandible, but in one white-wing the muscle was slightly +expanded on the right side and it could be seen in lateral view. The +homologous muscle in _Columba palumbus_ apparently is consistently +visible in lateral view. (See Rooth, 1953, fig. 6.) + +~_M. pterygoideus dorsalis medialis._~--The origin is fleshy on the +dorsolateral surface of the palatine immediately anterior to the +pterygoid and also on the anterior, dorsolateral, posterior and +ventromedial surfaces of the pterygoid. The insertion is fleshy on the +ventromedial surface of the lower mandible and the anterior surface of +the internal angular process immediately dorsal to the insertion of _M. +pterygoideus ventralis lateralis_. + +~_M. pterygoideus dorsalis lateralis._~--The origin is fleshy from the +dorsolateral surface of the palatine, anterior to the origin of _pars +medialis_ and the insertion is by means of an aponeurosis on the medial +surface of the lower mandible, lateral to the insertion of _M. +pterygoideus ventralis lateralis_. The aponeurosis crosses the medial +side of the insertion of _M. pterygoideus dorsalis medialis_. The +fibers run in a posteroventrolateral direction and insert on the +ventromedial side of the aponeurosis (figs. 1, 6, 8, 9, 13-22). + +In one individual, a Mourning Dove, the origin of _pars lateralis_ of +_M. pterygoideus dorsalis_ extended to the pterygoid. With this one +exception the muscle was uniform throughout the several species. + +~_M. adductor mandibulae externus._~--This is the most complex muscle +in the jaw owing to its system of tendons and aponeuroses. Three +divisions of this muscle were described by Lakjar (1926:45-46) and the +divisions appear to be distinguishable in the doves, but there is no +clear line of demarcation for any of the parts and the following +description is based upon my own attempts to delineate the muscle. + +~_M. adductor mandibulae externus superficialis._~--The origin is +fleshy from the most lateral area of the temporal fossa. Dorsally the +origin is bounded by the base of the postorbital process and ventrally +by the temporal process. The fibers converge upon a tendon that passes +beneath the postorbital ligament and runs anteriorly among the fibers +of _pars profundus_. The insertion is tendinous on the dorsal surface +of the lower mandible in common with the dorsal aponeurosis of _pars +profundus_. The insertion is immediately anterior to the ventral +aponeurosis of _pars profundus_ near the medial edge of the dorsal +surface on a tubercle at the posterior end of the dorsal ridge of the +lower mandible. + +~_M. adductor mandibulae externus medialis._~--The origin is by a flat, +heavy tendon from the temporal process. The tendon is attached almost +vertically on the temporal process. It twists approximately 130 deg. as +it runs anteriorly, and becomes a thin aponeurosis, which gives rise on +its dorsal and ventral surfaces to many fibers that insert in a +fan-shaped area on the mandibular fossa. Fibers from the dorsal and +dorsomedial sides of the heavy tendon run rostrad and insert on the +ventral surface of the dorsal aponeurosis of _pars profundus_. From the +ventral surface the most posterior fibers converge on an aponeurosis +that inserts on a transverse crista on the dorsal surface of the +mandible immediately lateral to the ventral aponeurosis of _pars +profundus_ and dorsal to the insertion of ~_M. adductor mandibulae +posterior_~. The more anterior fibers insert fleshily on the mandibular +fossa. The tendon of origin is actually one with the ventral +aponeurosis of _pars profundus_, which is situated in a horizontal +plane. The insertion is primarily a fleshy attachment on the mandibular +fossa. Some of the fibers that arise on the dorsomedial and lateral +surfaces of the tendon of origin attach to another tendon, which +inserts in the midline of the mandibular fossa on a small tubercle near +the anterior end. Also, there is insertion by an aponeurosis anterior +to _M. adductor mandibular posterior_ as stated above. Fibers attach to +the dorsal and ventral side of the aponeurosis. + +~_M. adductor mandibulae externus profundus._~--The origin is fleshy +from the medial surface of the temporal fossa, the posterior wall of +the orbit and the otic process of the quadrate. The origin is bounded +laterally by the origin of _pars superficialis_ and medially by the +origin of _M. pseudotemporalis superficialis_. Ventrally the muscle +lies against its own ventral aponeurosis, which originates on the +posterior wall of the orbit immediately above the articulation of the +otic process of the quadrate, and which also receives many fibers from +the surface of the quadrate. The insertion is primarily by means of two +aponeuroses. The most dorsal aponeurosis inserts on a tubercle at the +posterior tip of the dorsal edge of the mandible. The lateral tendon of +_M. pseudotemporalis superficialis_ converges with the aponeurosis. It +is superficial and there are no fibers on its dorsal surface. The +ventral aponeurosis inserts on a crista immediately below the insertion +of the dorsal aponeurosis. It receives fibers on its ventral surface +from the otic process of the quadrate, and on its dorsal surface gives +rise to fibers that insert on the dorsal aponeurosis (figs. 2, 3, 5, 9, +10, 11, 13-18). + +The tendon of insertion of _pars medialis_ of _M. adductor mandibulae +externus_ does not become a superficial aponeurosis posteriorly in the +Zenaida Dove as it does in the Mourning and White-winged doves. + +~_M. pseudotemporalis profundus._~--The origin is fleshy from the +medial and partially from the dorsal surface of the lower mandible. The +origin is almost completely anterior to and partly dorsal and ventral +to the medial (most anterior) insertion of _M. pseudotemporalis +superficialis_. The anterior margin of the origin is at the point where +the mandibular ramus of the trigeminal nerve enters the mandible. +Posteriorly the origin is bounded by the insertion of _M. adductor +mandibulae posterior_, and ventrally by a ridge that is situated about +halfway down the medial side of the mandible. The insertion is by +aponeurosis on the tip of the orbital process of the quadrate and +fleshily on the anterior surface of the same process. The aponeurosis +extends about three-fifths of the distance along the muscle and it is +dorsal or superficial to all of the fibers. Many fibers insert on the +ventral side of the aponeurosis (figs. 1, 5, 13, 14, 15, 16, 21 and +22). + +This muscle is the most variable of all the jaw muscles. In the +Mourning Dove the muscle appears rather slender in dorsal view and in +the White-winged Dove has an enlarged lateral belly that gives the +appearance of a thicker muscle. In the Zenaida Dove _M. +pseudotemporalis profundus_ is intermediate in shape between those of +the other two species. This muscle will be discussed in detail later. + +~_M. protractor pterygoidei._~--The origin is fleshy from the junction +of the sphenoidal rostrum and the interorbital septum. Fibers converge +on the pterygoid in anteroventrolateral and posteroventrolateral +directions. The posterior edge of the muscle is in contact with _M. +protractor quadrati_ with which its fibers mingle. The insertion is +fleshy on the posterior surface of the lateral half of the pterygoid to +its articulation with the body of the quadrate (figs. 6, 8, 9, 11, +13-20). + +~_M. depressor mandibulae superficialis medialis._~--The origin is +fleshy from the lateral edge of the basioccipital where the muscle is +attached to _Ligamentum depressor mandibulae_ and extends in a lateral +direction to a point where the structures involved turn dorsad. The +insertion is by fibers and a light aponeurosis on the crista that is +situated on the posteroventromedial edge of the lower mandible. + +~_M. depressor mandibulae superficialis lateralis._~--The origin is +fleshy from the squamosal region, slightly posteroventral to the origin +of _M. adductor mandibulae externus superficialis_. A thin aponeurosis +lies medial to the muscle fibers. The insertion is by means of an +aponeurosis that becomes tendonlike along the posteroventrolateral +crista and the posteriormost part of the ventral edge of the lower +mandible. + +~_M. depressor mandibulae medialis._~--The origin is fleshy from the +lateral and ventral surfaces of _Ligamentum depressor mandibulae_. The +insertion is fleshy on the posterior surface of the lower mandible, +posterodorsal to the insertions of _partes superficialis medialis et +lateralis_ (figs. 4, 9, 10, 13 and 14). + +The parts of _M. depressor mandibulae_ are difficult to distinguish +from one another because of considerable intermingling of fibers. + +~_M. pseudotemporalis superficialis._~--The origin is fleshy from the +posterior wall of the orbit, dorsal to the foramen of the trigeminal +nerve, lateral to the origin of _M. protractor quadrati_ and medial to +_M. adductor mandibulae externus profundus_. The insertion is by means +of an aponeurosis that bifurcates at the point of contact with the +mandibular ramus of the trigeminal nerve, which is at the level of the +orbital process of the quadrate (except in the Mourning Dove where the +division is more anterior), and which inserts as two tendons on the +dorsomedial edge of the lower mandible posterior to the insertion of +_M. pseudotemporalis profundus_. The lateral tendon is superficial to +the dorsomedial edge of _M. adductor mandibulae externus_, and +converges with the aponeurosis of _pars profundus_ of that muscle and +inserts with it on a tubercle near the dorsomedial edge of the +mandible anterior to the insertion of _M. adductor mandibulae +posterior_ as mentioned before. The anterior half of the medial tendon +lies ventral to the lateral edge of _M. pseudotemporalis profundus_ and +the mandibular ramus of the trigeminal nerve. All of the fibers of the +muscle insert on the posteroventral surface of the aponeurosis before +it divides. Part of _M. pseudotemporalis profundus_ also lies ventral +to the medial tendon of _M. pseudotemporalis superficialis_ and, in +effect, the tendon is imbedded in the substance of _M. pseudotemporalis +profundus_ as it proceeds anteriorly. The trigeminal nerve leaves a +slight impression on the ventral surface of the muscle near its origin +(figs. 1, 3, 11, 13, 14, 15 and 16). + +~_M. adductor mandibulae posterior._~--The origin is fleshy from the +anterodorsal and anterior surfaces of the quadrate body, from the +anterodorsolateral, medial and anterior surfaces of the orbital process +of the quadrate. The muscle also has an origin from the otic process of +the quadrate, partly fleshy and partly by a slight aponeurosis. The +insertion is fleshy on the dorsal and lateral surfaces of the mandible +immediately anterior to the articulating surface. This muscle also has +extensive insertion on the medial side of the lower mandible dorsal to +the insertion of _M. pterygoideus dorsalis medialis_ and posterior to +the origin of _M. pseudotemporalis profundus_ (figs. 1, 3, 5, 17, 18, +19 and 20). + +The fibers of _M. pseudotemporalis profundus_ can be distinguished from +the fibers of _M. adductor mandibulae posterior_ because the +pterygoideus nerve passes between the two (Lakjar, 1926:55). Rooth +(1953:255-256) considers as part of this muscle the ventral aponeurosis +of _pars profundus_ of _M. adductor mandibulae externus_ and all the +fibers ventral to it. But I could not justify the inclusion of that +aponeurosis as part of _M. adductor mandibulae posterior_ in the doves +because none of the fibers of _M. adductor mandibulae posterior_ as I +have described it were attached to that particular aponeurosis. + +~_M. protractor quadrati._~--The origin is fleshy from the posterior +wall of the orbit medial to the foramen of the trigeminal nerve and +also medial to the origin of _M. pseudotemporalis superficialis_. The +origin describes an arc in the horizontal plane until it reaches the +interorbital septum and the optic nerve. The insertion is fleshy on the +posteromedial edge of the body of the quadrate and the orbital process +of the quadrate and on the otic process of the quadrate. The muscle +also inserts on the ventromedial surface of the orbital process of the +quadrate and the adjacent area of the body of the quadrate (figs. 5, 7, +9, 11, 13-18). + +_M. protractor quadrati_ possesses many fibers that arise from _M. +protractor pterygoidei_. Consequently, it is difficult to determine the +exact extent of the origin or the insertion of either muscle. + + +ACTION OF JAW MUSCLES + +~_M. pterygoideus ventralis._~--Contraction of this muscle retracts the +upper mandible by moving the palatine posteriorly, and simultaneously +adducts the lower mandible. + +~_M. pterygoideus dorsalis._~--This muscle functions in essentially the +same manner as _M. pterygoideus ventralis_. The result of having a part +of its origin on the pterygoid as well as on the palatine is to +facilitate retraction of the upper mandible. + +~_M. adductor mandibulae._~--This is the chief adductor of the lower +mandible and the muscle functions solely in that capacity. In birds +having great crushing ability, this muscle is much larger and more +powerful and the skull is reinforced behind the quadrate in order to +withstand the pressure of the lower mandible against the quadrate +during adduction (Sims, 1955:374 and Bowman, 1961:219-222). + +~_M. pseudotemporalis profundus._~--With origin and insertion on highly +movable bones, this muscle, when it contracts, retracts the upper +mandible and adducts the lower mandible. Like the pterygoid muscles, +this muscle, by itself, would allow the bird to grasp objects by means +of its mandibles. However, _M. pseudotemporalis profundus_ could +produce a more powerful grip because it takes origin farther anteriorly +on the lower mandible. + +~_M. protractor pterygoidei._~--Contraction of _M. protractor +pterygoidei_ pulls the pterygoid anteromedially and causes it to slide +forward along the sphenoidal rostrum. This action aids in protraction +of the upper mandible. + +~_M. depressor mandibulae._~--The depressor of the lower mandible is +the sole muscle other than _M. geniohyoideus_ involved in the function +of abducting the lower jaw of doves. Its size can be correlated +especially well with feeding habits of the bird. Other birds that force +their closed mandibles into fruit, wood or the earth and then forcibly +open them, belong to groups possessing enlarged depressors. Contraction +of the muscle pulls the postarticular (retroarticular) process upward +with the resultant downward movement of that part of the mandible which +is anterior to the articulation. Since there is no "gaping" in doves +the muscle is only large enough to overcome the inherent tone of the +relaxed adductor muscles. + +In some non-passerine species as well as in certain passerines the +muscle also serves to raise the upper jaw by acting on the quadrate, +which is capable of rotating vertically on its otic process. Especially +in the gapers, where resistance is offered near the tip of the lower +mandible, contraction of the muscle pulls the entire mandible dorsad +thus forcing the jugal and palatal struts forward (Zusi, 1959:537-539). +The action supplements that of _Mm. protractor pterygoidei et quadrati_ +and is enhanced by anterior migration of the origin of _M. depressor +mandibulae_. + +There is no lifting action involved in contraction of the depressor +muscle in doves for two reasons--(A) the origin of the muscle is +situated much too far posteriorly on the skull, and, more important, +(B) the quadrate is not hinged for vertical movement. As will be +discussed later, it moves only in a horizontal plane. + +~_M. pseudotemporalis superficialis._~--Like _M. adductor mandibulae_, +this muscle performs only the one function of adducting the lower +mandible, and like _M. pseudotemporalis profundus_ it is a synergist of +that muscle. + +~_M. adductor mandibulae posterior._~--Although this muscle undoubtedly +acts as an adductor of the lower mandible, I believe that, because of +its disadvantageous insertion so near the articulation, its main +function must be concerned with firming the mandible against the +quadrate. This is to say that its function is partially that of a +ligament. + +~_M. protractor quadrati._~--When _M. protractor quadrati_ contracts, +the quadrate bone is swung medially. This action, as mentioned +previously, results in protraction of the upper jaw, and, as a +consequence, its action supplements the action of _M. protractor +pterygoidei_. + + +CRANIAL OSTEOLOGY + +The ability of most birds to protract the upper mandible, and the +structure of the skull which enables them to do so are responsible for +common reference to the skull as "kinetic" (Beecher, 1951a:412; Fisher, +1955:175). The movement is effected by muscular action on a series of +movable bones that exert their forward force on the upper mandible, +which in turn swings on a horizontal hinge, the "naso-frontal hinge," +at the base of the beak. The bone initiating the movement is the +quadrate, which is hinged posteriorly by its otic process and which +ordinarily swings up or down depending on the muscle or muscles being +contracted at any given moment. The upward swing of the quadrate pushes +the jugal bar, which is attached to its lateral tip, along its +longitudinal axis, in an anterodorsal direction, and the force is +transferred to the upper mandible, which is thereby elevated. A +synergetic mechanism is simultaneously initiated by the same bone--the +quadrate. Since the quadrate body articulates with the pterygoid, the +upward movement forces the pterygoid to slide along a ridge in the +ventral midline of the cranium, the sphenoidal rostrum, thus pushing +the palatine forward and exerting an upward push on the upper mandible. + +In the columbids the quadrate has a bifurcated otic process that +functions as the hinge. The posterior tips of the forks are situated +almost vertically (one above the other) and the movement of the +quadrate is not so much up and down, or vertical, as it is horizontal +(fig. 12). When the quadrate moves medially the upper mandible is +protracted; a lateral movement results in retraction. There is a +slight, almost negligible, upward movement of the quadrate. The +movements of the various bony elements were observed on a skull that +had been made flexible by boiling in water for a minute as suggested by +Beecher (1951a:412). + +Also in the columbids the naso-frontal hinge is not constructed in the +same manner as it is in many other birds as there is not a simple hinge +across the entire base of the beak. In fact, there is no true hinge at +all in the area of the nasals, but those bones are extremely thin and +they bend or flex under pressure. Actually, the hinge is double or +divided. One part is on either side of the nasals. The hinges are +situated at the posterodorsal tips of two thin processes of the +maxillary bones and the appearance is not unlike that of half a span of +a suspension bridge having the hinges at the tops of the towers. +Several other species of birds share this type of hinge construction +with columbids. + +The movement of the lower jaw is, of course, the primary operation +involved in opening the mouth. The lower jaw possesses a deep fossa at +its posterior end, or on its posterodorsal surface, which articulates +with the body of the quadrate bone. The length of that part of the +mandible extending behind the articulation is directly correlated with +the resistance offered the mandible in opening, since it is on the +posterior extension that the depressor of the lower mandible inserts. +The larger the muscle the more surface is needed for attachment. Also +the added length of the mandible posterior to the articulation serves +as a lever in opening the mandible, and the fulcrum is moved relatively +farther forward. + +In birds lacking resistance to abduction of the lower mandible, as in +doves, it is nevertheless necessary for a slight postarticular process +to remain for the insertion of a small depressor muscle which, as +mentioned previously, is necessary to counteract the relaxed adductor +muscles of the lower jaw. + +There are many exceptions to the rule that birds have kinetic skulls, +and usually a secondary fusion and reinforcement of bones around the +hinge has limited or eliminated all movement. Sims (1955) describes the +Hawfinch's immobile upper jaw, which is used as a powerful press in +cracking the stones of fresh fruit. Skulls of woodpeckers have been +modified somewhat in the same manner as a result of their foraging and +nesting habits (Burt, 1930). + +The two most distantly related members of the genera under +investigation are the White-winged Dove, _Zenaida asiatica_, and the +Mourning Dove, _Zenaidura macroura_. They were chosen to demonstrate +differences and likenesses in proportions of members of the genera. + +Ten measurements were taken on each skull, but simple observation +reveals that, in relation to total length of the skull, the beak of the +White-winged Dove is longer than that of the Mourning Dove. Tip of +upper mandible to base of beak averaged 48.6 and 42.9 per cent of the +total length of the skull in the White-winged Dove and Mourning Dove, +respectively. The position of the jugal bar has remained about the same +with respect to the cranial part of the skull, and the entire cranial +part of the skull is almost the same shape in the species studied. + +Likewise, in the White-winged Dove the distance from the anterior tip +of the lower mandible to the anterior part of _M. adductor mandibulae +externus_ is relatively longer in relation to the length of the lower +mandible than in the Mourning Dove. Finally, the position of the jugal +with respect to the naso-frontal hinge is about the same in the two +species. + +Measurements and calculations indicate that the longer beak of the +White-winged Dove as compared with the Mourning Dove is a function of +the beak itself, not of differences in other parts of the skull. +Measurements of skulls of Eared and Zenaida doves support this view. + + +OTHER MORPHOLOGICAL FEATURES + +In the species dissected, the only variable muscle that I consider +significant in revealing relationships is _M. pseudotemporalis +profundus_. It is markedly enlarged in the White-winged Dove in +relation to the homologous muscle in the Mourning Dove. The muscle is +enlarged in such a manner that a lateral expansion of its mass is +apparent in superficial or dorsal view (compare figures 15 and 16). +This, of course, indicates a muscle with powerful contraction, which +has been unable to enlarge its circumference symmetrically because the +eye is immediately dorsal to the muscle. Therefore it has expanded +laterally. Ventral expansion is blocked by the presence of other +muscles, and medially there is no surface for the insertion of +additional fibers on the orbital process of the quadrate. + +The jaw musculature has been known for some time to be highly adaptive +(Beecher, 1951a and b, 1953; Bowman, 1961; Burt, 1930; Engels, 1940 and +Goodman and Fisher, 1962) and it would not be unreasonable, I think, to +expect the jaw muscles of closely related species with similar habits +to be similar. The beak of the White-winged Dove is longer in +proportion to the length and height of the skull (exclusive of the +beak) than is the beak of the Mourning Dove. The lengthened beak is +probably an adaptation for nectar-feeding, which has been documented by +McGregor, Alcorn and Olin (1962:263-264) while investigating +pollinating agents of the Saguaro Cactus (_Cereus giganteus_), and by +Gilman (1911:53) who observed the birds thrusting their bills into the +flowers of the plant. Gilman indicated, however, that he could not be +sure if the birds were seeking insects, pollen, or nectar. In any event +the lengthened bill probably facilitates getting food by birds that +probe parts of flowers. Hensley (1954:202) noted that both Mourning and +White-winged doves were "exceptionally fond of this source of +nourishment." But he also points out an "interesting correlation" +between the presence of the white-wings in the desert and the flowering +of the saguaro. During his studies the appearance of the first +white-wing preceded the opening of the first saguaro flower by two +days. The flowering and fruiting season lasted until August, the month +of termination of the white-wing breeding season. + +Since Hensley makes the correlation solely with the white-wings, I +assume that there is no other obvious correlation between plants and +birds among the remainder of the avifauna of the desert. Probably the +Mourning Dove has failed to adapt to nectar-feeding as yet, and the +White-winged Dove is the primary exploiter of this food niche. It +should be noted, also, that the head of the Mourning Dove is smaller +than the white-wing's, and perhaps there is no need for an elongated +beak for reaching deeply into the flowers. + +The lengthened bill should produce no difficulties in protraction of +the upper mandible and depression of the lower for the reason that in +the dove there is no known resistance offered to these movements. The +genus _Icterus_ furnishes an example wherein resistance is met in the +process of opening the mandibles; individuals of this genus thrust +their closed bill into certain fruits and forcibly open their mandibles +against the resistance of the pulp by strong protraction and +depression, thus permitting the juices of the fruit to lake and +ultimately to be consumed (Beecher, 1950:53). Beecher refers to the +technique used in fruit-eating as "gaping." The result of gaping in +_Icterus_ should be the presence of a more massive set of muscles +concerned with protraction and depression than is found in non-gaping +groups. Beecher found the situation to be exactly as expected in that +genus and in other genera which also gape. Meadowlarks (_Sturnella_) +and caciques (_Archiplanus_) gape and pry in soil and wood respectively +(Beecher, 1951a:422 and 426). + +The lengthened beak would be a problem when the White-winged Dove +attempted to pick up objects such as seeds, which do in fact constitute +the largest percentage of its diet in spite of its nectar-feeding +habit. A similar situation exists in the genus _Icterus_, which is +primarily adapted for gaping even though it shows a preference for +insects when they are abundant (Beecher, 1950:53). The lengthened beak +could be compensated for by (A) migration of the anterior end of the +jugal bar toward the rostral tip of the bill and away from the +fronto-nasal hinge with a simultaneous enlargement of the adductor +muscles of the lower mandible, or (B) enlargement of the one muscle +that functions simultaneously as an efficient retractor of the upper +mandible and adductor of the lower mandible, namely _M. +pseudotemporalis profundus_. _Mm. pterygoideus dorsalis et lateralis_ +perform the same function, but because of their position on the lower +mandible they, apparently, are stronger retractors of the upper +mandible than they are adductors of the lower. + +It will be recalled that the jugal bar bears the same, or nearly the +same, relationship to the cranium in the white-wing as it does in the +Mourning Dove and that the heads, excluding the beaks of both species, +are of nearly the same proportions. Also, _Mm. adductor mandibulae +externus_ and _pseudotemporalis superficialis_, the chief adductor +muscles of the lower mandible, were not noticeably enlarged in the +white-wing. It is also important to note that other combinations of +migration of bone and/or enlargement of muscles could successfully +solve the problem of providing sufficient leverage for the proper +functioning of the lengthened mandibles, but it is my thesis that the +second alternative sufficed for seed-eating habits and that that is the +adaptation that was established; it is, in fact, the only one present +in the White-winged Dove. + +It is unlikely that this enlarged muscle and beak are the remains of +another series of jaw muscles that have converged toward the condition +in Mourning Doves. Columbids are almost unquestionably monophyletic, +and two lines would have had to diverge and then converge. There is no +evidence for such an evolutionary occurrence. + + +GENERIC RELATIONSHIP + +An attempt will be made here to summarize all the available evidence, +direct or indirect, which bears on the problem of relationship of these +genera. The original dissections which are discussed in this report are +only valuable as one more bit of evidence concerning one characteristic +that aids in clarification of generic relationship, and it is only in +conjunction with other evidence that any satisfactory conclusion may be +forthcoming. + + +Morphology + +My dissections demonstrated that, in relation to the size of the doves, +the jaw musculature of all the specimens investigated was so nearly +alike that only one major difference was detected. _M. pseudotemporalis +profundus_ appeared to be enlarged in the White-winged Dove. This might +have been predicted, since the white-wing was also shown to possess an +elongated beak, presumably an adaptation for nectar-feeding, which +would necessitate additional muscle development in order to compensate +for the added length. Measurements recorded from several skulls +indicated that the heads of the birds (excluding the beak) are nearly +proportional. + +Perhaps plumage patterns are the most widely used characters for +determining generic relationships of birds. Ridgway (1916:339-385) +followed the columbid classification of Salvadori (1893) using plumage +patterns and body proportions to distinguish between the genera. In the +genus _Zenaidura_ he included the unique specimen _Zenaidura +yucatanensis_, and he placed _auriculata_ in _Zenaida_. The +White-winged Dove was referred to a separate genus, _Melopelia_. He +described the genus _Zenaidura_ in the following manner: + + "Plumage of head, neck and under parts soft and blended; + bare orbital space moderate, broadest beneath eyes. + Coloration plain, the proximal secondaries (sometimes + adjacent wing-coverts and scapulars also) spotted with + black; rectrices (except middle pair) with a black band + across postmedian portion, the apical portion paler gray + than basal portion, sometimes white; a small black + subauricular spot; adult males with head, neck and anterior + under parts more or less vinaceous and sides of neck glossed + with metallic purple." + +He noted that the plumage of _Zenaida_ was almost precisely as +described for _Zenaidura_. Also, although all members of _Zenaida_ +reputedly possessed twelve rectrices, a characteristic of the genus, it +was later found that _auriculata_ possessed fourteen rectrices. The +species was promptly placed in the genus _Zenaidura_ by Peters +(1934:213-215). In plumage and coloration, _Melopia_ was described as +similar to _Zenaida_ and _Zenaidura_ but without black spots on the +wings. + +The White-winged Dove also has twelve rectrices, but Bond (1940:53) and +Goodwin (1958:330-334) considered the number and shape of rectrices to +be of minor importance when compared to the homologous markings of the +plumage. Goodwin stated that his conclusion was emphasized by the fact +that the tail of _auriculata_ is intermediate in length and shape +between those of _macroura_ and _aurita_. In summary Goodwin "lumped" +the genera _Zenaida_ and _Zenaidura_ under the genus _Zenaida_. + + +Nidification + +It has been adequately documented that members of these genera closely +resemble one another in their nesting and egg-laying habits. Bent +(1932:407, 417), Davie (1889:157), Goss (1891:242) and Nice (1922:466) +have described the two, white eggs of the clutch of the Mourning Dove. +They have also noted that their nests are composed mainly of twigs and +may be constructed in trees, shrubs or on the ground. The Eared Dove +has nearly identical habits (Bond, 1961:104), and a similar situation +exists with the Zenaida Dove (Audubon, 1834:356; Bent, 1932:418-419). + +Like the other species, White-winged Doves lay two white or buffy eggs +per clutch and build frail nests of sticks (Bent, 1932:431; Wetmore, +1920:141; Baird, Brewer and Ridgway, 1905:377). + +The point to be made here is simply this: If the species in question +are to be considered congeneric then it might reasonably be expected +that they would display some similarity in nidification and egg-laying. +If their habits varied considerably it would not necessarily mean that +their relationship was more distant, but similarities can usually be +considered indicative of affinities because they are the phenotypic +expression of the partially unaltered genotype of the common ancestor. + + +Interbreeding + +Intergeneric crosses of columbids in captivity are common, but in +nature there is little evidence that even interspecific crosses occur. +Only one apparent hybrid between members of the genus _Zenaida_ and +genus _Zenaidura_ has ever been discovered. The individual was taken on +the Yucatan peninsula of Mexico, and was described and named as a new +species (_Zenaidura yucatanensis_). + +Salvadori (1893:373), Ridgway (1916:353) and Peters (1934:213-215) +agree that _Zenaidura yucatanensis_ Lawrence is a hybrid between +_Zenaidura macroura marginella_ and _Zenaida aurita yucatanensis_. +Ridgway (1916:355), however, notes that "... If _Zenaidura +yucatanensis_ Lawrence should prove to be really a distinct species, +and not a hybrid ... unquestionably _Zenaida_ and _Zenaidura_ can not +be separated generically, since the former is in every way exactly +intermediate between the two groups." In the event that the unique type +is a hybrid, the very fact of its existence supports the hypothesis +that the genera are more closely related than is currently recognized. + + +Serology + +There have been no investigations having as their sole purpose the +clarification of the relationship of the genera _Zenaida_ and +_Zenaidura_. But some work has involved the comparison of the antigenic +content of individual columbids with the antigenic content of a member +of another species of the same family. + +Irwin and Miller (1961) tested, along with other columbids, members of +_Zenaida_ and _Zenaidura_ for presence of, 1) species-specific antigens +of _Columba guinea_ (in relation to _Columba livia_) which are +designated A, B, C and E, and, 2) species-specific antigens of _C. +livia_ (in relation to _C. guinea_) which are designated A', B', C' and +E'. + +In the first test all five species of _Zenaida_ and _Zenaidura_ +possessed antigens A and C, and all but _auriculata_ possessed E. None +of the species gave evidence of the presence of the B antigen of _C. +guinea_ in their blood. In the latter test only _macroura_ had A', only +_asiatica_ had B' (_aurita_ was not tested for B'), and none had C' or +E'. + +These results would indicate that the five species are similar +regarding antigenic content of the blood, and the variation is not +consistent within one or the other genus as presently known. + + +SUMMARY AND CONCLUSION + +The avian genus _Zenaida_ is currently considered to be distinct from +the genus _Zenaidura_ by most columbid taxonomists. The jaw muscles of +six Mourning Doves (_Zenaidura_) and five White-winged Doves +(_Zenaida_) were investigated as to differences and similarities that +might clarify the relationships of the genera. The sizes and +proportions of skulls were also considered in 37 Mourning and +White-winged doves and two Eared Doves. Larger size of _M. +pseudotemporalis profundus_, the muscle that functions simultaneously +as an adductor of the lower jaw and retractor of the upper jaw, in the +White-winged Dove was the character found in the jaw musculature that +could be used to support the contention that _Zenaidura_ and _Zenaida_ +represent distinct genera. Larger size of this muscle in the white-wing +seems to be related to its elongated beak. The long beak apparently is +used for nectar-feeding in flowers of the Saguaro Cactus. + +Excluding the beak, skulls of the white-wing and Mourning doves are of +nearly the same shape. Previous investigators have shown that in +_Zenaida_ and _Zenaidura_ plumage patterns are similar, nesting habits +and eggs are nearly identical, blood proteins are similar, and one +"intergeneric" hybridization in nature is known. + +Consequently, it is concluded that species of the two alleged genera +are congeneric, and I agree with Goodwin (1958) that the genus +_Zenaida_ (Bonaparte, 1838:41) should include the Mourning Dove, Eared +Dove, Socorro Dove, Zenaida Dove, and White-winged Dove. Their Latin +binomina are _Zenaida macroura_, _Zenaida auriculata_, _Zenaida +graysoni_, _Zenaida aurita_, and _Zenaida asiatica_, respectively. + +[Illustration: FIG. 1. Medial view of left ramus of lower +mandible of Mourning Dove. x 2-1/2. + +FIG. 2. Lateral view of right ramus of lower mandible of +Mourning Dove. x 2-1/2.] + +[Illustration: FIG. 3. Dorsal view of lower mandible of +Mourning Dove. x 2-1/2. + +FIG. 4. Ventral view of lower mandible of Mourning Dove. +x 2-1/2.] + +[Illustration: FIG. 5. Dorsal view of right quadrate of +Mourning Dove. x 5. + +FIG. 6. Dorsal view of right pterygoid of Mourning Dove. x 5. + +FIG. 7. Ventral view of right quadrate of Mourning Dove. x 5. + +FIG. 8. Ventral view of right pterygoid of Mourning Dove. x 5.] + +[Illustration: FIG. 9. Right lateral view of skull of Mourning +Dove. x 2-1/2. + +FIG. 10. Ventral view of skull of Mourning Dove. x 2-1/2.] + +[Illustration: FIG. 11. Cross section of skull of Mourning Dove; +anterior view. x 2-1/2. + +FIG. 12. Dorsal view of right quadrate of Mourning Dove showing +movement which protracts the upper mandible (broken line). x 5.] + +[Illustration: FIG. 13. Right lateral view of the jaw musculature of +the White-winged Dove; superficial layer, x 5. + +FIG. 14. Right lateral view of the jaw musculature of the Mourning +Dove; superficial layer. x 5.] + +[Illustration: FIG. 15. Dorsal view of the jaw musculature of the +White-winged Dove (right side); superficial layer. x 5. + +FIG. 16. Dorsal view of the jaw musculature of the Mourning Dove +(right side); superficial layer. x 5.] + +[Illustration: FIG. 17. Dorsal view of the jaw musculature of the +White-winged Dove (right side); middle layer. x 5. + +FIG. 18. Dorsal view of the jaw musculature of the Mourning Dove +(right side); middle layer. x 5.] + +[Illustration: FIG. 19. Dorsal view of the jaw musculature of the +White-winged Dove (right side); deep layer. x 5. + +FIG. 20. Dorsal view of the jaw musculature of the Morning Dove (right +side); deep layer. x 5.] + +[Illustration: FIG. 21. Ventral view of the jaw musculature of the +White-winged Dove (_M. depressor mandibulae_ not shown). x 5. + +FIG. 22. Ventral view of the jaw musculature of the Mourning Dove +(_M. depressor mandibulae_ not shown). x 5.] + + + + +LITERATURE CITED + + +ADAMS, L. A. + 1919. A memoir on the phylogeny of the jaw muscles in recent and + fossil vertebrates. Annals New York Acad. Sci., 28:51-166. + +AUDUBON, J. J. + 1834. Ornithological biography. Vol. II. Adam & Charles Black, + Edinburgh, xxxii + 588 pp. + +BAIRD, S. F., BREWER, T. M., and RIDGWAY, R. + 1905. The land birds of North America. Little, Brown, and Company, + Boston, 560 + xxvii pp. + +BEECHER, W. J. + 1950. Convergent evolution in the American orioles. Wilson Bull. + 62:51-86. + + 1951a. Adaptations for food-getting in the American blackbirds. Auk, + 68:411-440. + + 1951b. Convergence in the Coerebidae. Wilson Bull., 63:274-287. + + 1953. A phylogeny of the oscines. Auk, 70:270-333. + +BENT, A. C. + 1932. Life histories of North American gallinaceous birds. Bull. + U. S. Nat. Mus., 162:xi + 490 pp., 93 pls. + +BONAPARTE, C. L. + 1838. Geographical and comparative list of the birds of Europe and + North America. John Van Voorst, London, vii + 68 pp. + +BOND, J. + 1961. Birds of the West Indies. Houghton Mifflin Company, Boston. + 256 pp., 8 pls., 186 figs. + +BOWMAN, R. I. + 1961. Morphological differentiation and adaptation in the Galapagos + finches. Univ. California Publ. Zool., 58:vii + 302 pp., + 22 pls., 74 figs., 63 tables. + +BURT, W. H. + 1930. Adaptive modifications in the woodpeckers. Univ. California + Publ. Zool., 32:455-524. + +CAIN, A. J. + 1956. The genus in evolutionary taxonomy. Syst. Zool., 5:97-109. + + 1959. Taxonomic concepts. Ibis, 101:302-318. + +DAVIE, O. + 1889. Nests and eggs of North American birds. Hann & Adair, + Columbus, 455 + xii pp., 13 pls. + +EDGEWORTH, F. H. + 1935. The cranial muscles of vertebrates. Cambridge Univ. Press, + viii + 493 pp., 841 figs. + +ENGELS, W. L. + 1940. Structural adaptations in thrashers (Mimidae: genus + _Toxostoma_) with comments on interspecific relationships. + Univ. California Publ. Zool., 42:341-400, 24 figs., 11 tables. + +FISHER, H. I. + 1955. Some aspects of the kinetics in the jaws of birds. Wilson + Bull., 67:175-188, 4 figs., 6 tables. + +GADOW, H. + 1891. Vogel: I. Anatomischer Theil. Bronn's Klassen und Ordnungen + des Thier-Reichs. C. F. Winter, Leipzig, 6:1-1,008, many + figs., 59 pls. + +GILMAN, M. F. + 1911. Doves on the Pima Reservation. Condor, 13:51-56. + +GOODMAN, D. C., and FISHER, H. I. + 1962. Functional anatomy of the feeding apparatus in waterfowl. + Southern Illinois Univ. Press, Carbondale, xii + 193 pp. + +GOODWIN, D. + 1958. Remarks on the taxonomy of some American doves. Auk, + 75:330-334. + +GOSS, N. S. + 1891. History of the birds of Kansas. Geo. W. Crane & Co., Topeka, + 692 pp., 35 pls. + +HENSLEY, M. M. + 1954. Ecological relations of the breeding bird populations of the + desert biome of Arizona. Ecol. Monographs, 24:185-207. + +HOFER, H. + 1950. Zur Morphologie der Kiefermuskulatur der Vogel. Zool. Jahrb. + Jena (Anat.), 70:427-556, 44 figs. + +IRWIN, M. R., and MILLER, W. J. + 1961. Interrelationships and evolutionary patterns of cellular + antigens in columbidae. Evolution, 15:30-43. + +JACKSON, A. S. + 1941. The mourning dove in Throckmorton County, Texas, Unpubl. + manuscript (Abstract). + +KIEL, W. H., JR., and HARRIS, J. T. + 1956. Status of the white-winged dove in Texas. Trans. 21st N. + Amer. Wildl. Conf., pp. 376-388. + +KNAPPEN. P. + 1938. Preliminary report on some of the important foods of the + mourning dove in the southeastern U. S. Trans. 3rd N. Amer. + Wildl. Conf., pp. 776-781. + +LAKJER, T. + 1926. Studien Uber die Trigeminus-versorgte Kaumuskulatur der + Sauropsiden. C. A. Reitzel Buchhandlung, Kopenhagen, 154 pp., + 26 pls. + +LEOPOLD, A. S. + 1943. Autumn feeding and flocking habits of the mourning dove in + southern Missouri. Wilson Bull., 55:151-154. + +MCGREGOR, S. E., ALCORN, S. M., and OLIN, G. + 1962. Pollination and pollinating agents of the saguaro. Ecology, + 43:259-267. + +NICE, M. M. + 1922. A study of the nesting of mourning doves. Auk, 39:457-474; + 40:37-58. + +PETERS, J. L. + 1934. The classification of some American pigeons. Condor, + 36:213-215. + + 1937. Check-list of birds of the world. Vol. III. Harvard Univ. + Press, Cambridge, xiii + 311 pp. + +ROOTH, J. + 1953. On the correlation between the jaw muscles and the structure + of the skull in _Columba palumbus_. Kon. Ned. Akad. Wet.; + Proc. Sect. Sci., Vol. VI, serie C, pp. 251-264. + +SALVADORI, T. + 1893. Catalogue of birds in the British Museum, 21:xvii + 676 pp., + 15 pls. + 17 pp. + +SHUFELDT, R. W. + 1890. The myology of the raven. MacMillan & Co., London, xix + 343 + pp., 76 figs. + +SIMS, R. W. + 1955. The morphology of the head of the hawfinch. Bull. Brit. Mus. + (Nat. Hist.) Zool., 2:369-393. + +WETMORE, A. + 1920. Observations of the habits of the white-winged dove. Condor, + 22:140-146. + +ZUSI, R. L. + 1959. The function of the depressor mandibulae muscle in certain + passerine birds. Auk, 76:537-539. + + +_Transmitted June 3, 1963._ + + + + + * * * * * + +Transcriber's Notes + +Italicized text is shown within _underscores_. + +Bold italicized text is shown within ~_tildes and underscores_~. + + + + + + + + +End of the Project Gutenberg EBook of Jaw Musculature of the Mourning and +White-winged Doves, by Robert L. Merz + +*** END OF THIS PROJECT GUTENBERG EBOOK JAW MUSCULATURE--DOVES *** + +***** This file should be named 32018.txt or 32018.zip ***** +This and all associated files of various formats will be found in: + https://www.gutenberg.org/3/2/0/1/32018/ + +Produced by Chris Curnow, Joseph Cooper, Diane Monico, and +the Online Distributed Proofreading Team at +https://www.pgdp.net + + +Updated editions will replace the previous one--the old editions +will be renamed. + +Creating the works from public domain print editions means that no +one owns a United States copyright in these works, so the Foundation +(and you!) can copy and distribute it in the United States without +permission and without paying copyright royalties. Special rules, +set forth in the General Terms of Use part of this license, apply to +copying and distributing Project Gutenberg-tm electronic works to +protect the PROJECT GUTENBERG-tm concept and trademark. Project +Gutenberg is a registered trademark, and may not be used if you +charge for the eBooks, unless you receive specific permission. If you +do not charge anything for copies of this eBook, complying with the +rules is very easy. You may use this eBook for nearly any purpose +such as creation of derivative works, reports, performances and +research. They may be modified and printed and given away--you may do +practically ANYTHING with public domain eBooks. Redistribution is +subject to the trademark license, especially commercial +redistribution. + + + +*** START: FULL LICENSE *** + +THE FULL PROJECT GUTENBERG LICENSE +PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK + +To protect the Project Gutenberg-tm mission of promoting the free +distribution of electronic works, by using or distributing this work +(or any other work associated in any way with the phrase "Project +Gutenberg"), you agree to comply with all the terms of the Full Project +Gutenberg-tm License (available with this file or online at +https://gutenberg.org/license). + + +Section 1. General Terms of Use and Redistributing Project Gutenberg-tm +electronic works + +1.A. By reading or using any part of this Project Gutenberg-tm +electronic work, you indicate that you have read, understand, agree to +and accept all the terms of this license and intellectual property +(trademark/copyright) agreement. If you do not agree to abide by all +the terms of this agreement, you must cease using and return or destroy +all copies of Project Gutenberg-tm electronic works in your possession. +If you paid a fee for obtaining a copy of or access to a Project +Gutenberg-tm electronic work and you do not agree to be bound by the +terms of this agreement, you may obtain a refund from the person or +entity to whom you paid the fee as set forth in paragraph 1.E.8. + +1.B. "Project Gutenberg" is a registered trademark. It may only be +used on or associated in any way with an electronic work by people who +agree to be bound by the terms of this agreement. There are a few +things that you can do with most Project Gutenberg-tm electronic works +even without complying with the full terms of this agreement. See +paragraph 1.C below. There are a lot of things you can do with Project +Gutenberg-tm electronic works if you follow the terms of this agreement +and help preserve free future access to Project Gutenberg-tm electronic +works. See paragraph 1.E below. + +1.C. The Project Gutenberg Literary Archive Foundation ("the Foundation" +or PGLAF), owns a compilation copyright in the collection of Project +Gutenberg-tm electronic works. Nearly all the individual works in the +collection are in the public domain in the United States. If an +individual work is in the public domain in the United States and you are +located in the United States, we do not claim a right to prevent you from +copying, distributing, performing, displaying or creating derivative +works based on the work as long as all references to Project Gutenberg +are removed. Of course, we hope that you will support the Project +Gutenberg-tm mission of promoting free access to electronic works by +freely sharing Project Gutenberg-tm works in compliance with the terms of +this agreement for keeping the Project Gutenberg-tm name associated with +the work. You can easily comply with the terms of this agreement by +keeping this work in the same format with its attached full Project +Gutenberg-tm License when you share it without charge with others. + +1.D. The copyright laws of the place where you are located also govern +what you can do with this work. Copyright laws in most countries are in +a constant state of change. If you are outside the United States, check +the laws of your country in addition to the terms of this agreement +before downloading, copying, displaying, performing, distributing or +creating derivative works based on this work or any other Project +Gutenberg-tm work. The Foundation makes no representations concerning +the copyright status of any work in any country outside the United +States. + +1.E. Unless you have removed all references to Project Gutenberg: + +1.E.1. The following sentence, with active links to, or other immediate +access to, the full Project Gutenberg-tm License must appear prominently +whenever any copy of a Project Gutenberg-tm work (any work on which the +phrase "Project Gutenberg" appears, or with which the phrase "Project +Gutenberg" is associated) is accessed, displayed, performed, viewed, +copied or distributed: + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + +1.E.2. If an individual Project Gutenberg-tm electronic work is derived +from the public domain (does not contain a notice indicating that it is +posted with permission of the copyright holder), the work can be copied +and distributed to anyone in the United States without paying any fees +or charges. If you are redistributing or providing access to a work +with the phrase "Project Gutenberg" associated with or appearing on the +work, you must comply either with the requirements of paragraphs 1.E.1 +through 1.E.7 or obtain permission for the use of the work and the +Project Gutenberg-tm trademark as set forth in paragraphs 1.E.8 or +1.E.9. + +1.E.3. If an individual Project Gutenberg-tm electronic work is posted +with the permission of the copyright holder, your use and distribution +must comply with both paragraphs 1.E.1 through 1.E.7 and any additional +terms imposed by the copyright holder. Additional terms will be linked +to the Project Gutenberg-tm License for all works posted with the +permission of the copyright holder found at the beginning of this work. + +1.E.4. Do not unlink or detach or remove the full Project Gutenberg-tm +License terms from this work, or any files containing a part of this +work or any other work associated with Project Gutenberg-tm. + +1.E.5. Do not copy, display, perform, distribute or redistribute this +electronic work, or any part of this electronic work, without +prominently displaying the sentence set forth in paragraph 1.E.1 with +active links or immediate access to the full terms of the Project +Gutenberg-tm License. + +1.E.6. You may convert to and distribute this work in any binary, +compressed, marked up, nonproprietary or proprietary form, including any +word processing or hypertext form. However, if you provide access to or +distribute copies of a Project Gutenberg-tm work in a format other than +"Plain Vanilla ASCII" or other format used in the official version +posted on the official Project Gutenberg-tm web site (www.gutenberg.org), +you must, at no additional cost, fee or expense to the user, provide a +copy, a means of exporting a copy, or a means of obtaining a copy upon +request, of the work in its original "Plain Vanilla ASCII" or other +form. Any alternate format must include the full Project Gutenberg-tm +License as specified in paragraph 1.E.1. + +1.E.7. Do not charge a fee for access to, viewing, displaying, +performing, copying or distributing any Project Gutenberg-tm works +unless you comply with paragraph 1.E.8 or 1.E.9. + +1.E.8. You may charge a reasonable fee for copies of or providing +access to or distributing Project Gutenberg-tm electronic works provided +that + +- You pay a royalty fee of 20% of the gross profits you derive from + the use of Project Gutenberg-tm works calculated using the method + you already use to calculate your applicable taxes. The fee is + owed to the owner of the Project Gutenberg-tm trademark, but he + has agreed to donate royalties under this paragraph to the + Project Gutenberg Literary Archive Foundation. Royalty payments + must be paid within 60 days following each date on which you + prepare (or are legally required to prepare) your periodic tax + returns. Royalty payments should be clearly marked as such and + sent to the Project Gutenberg Literary Archive Foundation at the + address specified in Section 4, "Information about donations to + the Project Gutenberg Literary Archive Foundation." + +- You provide a full refund of any money paid by a user who notifies + you in writing (or by e-mail) within 30 days of receipt that s/he + does not agree to the terms of the full Project Gutenberg-tm + License. You must require such a user to return or + destroy all copies of the works possessed in a physical medium + and discontinue all use of and all access to other copies of + Project Gutenberg-tm works. + +- You provide, in accordance with paragraph 1.F.3, a full refund of any + money paid for a work or a replacement copy, if a defect in the + electronic work is discovered and reported to you within 90 days + of receipt of the work. + +- You comply with all other terms of this agreement for free + distribution of Project Gutenberg-tm works. + +1.E.9. If you wish to charge a fee or distribute a Project Gutenberg-tm +electronic work or group of works on different terms than are set +forth in this agreement, you must obtain permission in writing from +both the Project Gutenberg Literary Archive Foundation and Michael +Hart, the owner of the Project Gutenberg-tm trademark. Contact the +Foundation as set forth in Section 3 below. + +1.F. + +1.F.1. Project Gutenberg volunteers and employees expend considerable +effort to identify, do copyright research on, transcribe and proofread +public domain works in creating the Project Gutenberg-tm +collection. Despite these efforts, Project Gutenberg-tm electronic +works, and the medium on which they may be stored, may contain +"Defects," such as, but not limited to, incomplete, inaccurate or +corrupt data, transcription errors, a copyright or other intellectual +property infringement, a defective or damaged disk or other medium, a +computer virus, or computer codes that damage or cannot be read by +your equipment. + +1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the "Right +of Replacement or Refund" described in paragraph 1.F.3, the Project +Gutenberg Literary Archive Foundation, the owner of the Project +Gutenberg-tm trademark, and any other party distributing a Project +Gutenberg-tm electronic work under this agreement, disclaim all +liability to you for damages, costs and expenses, including legal +fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT +LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE +PROVIDED IN PARAGRAPH F3. YOU AGREE THAT THE FOUNDATION, THE +TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE +LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR +INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH +DAMAGE. + +1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a +defect in this electronic work within 90 days of receiving it, you can +receive a refund of the money (if any) you paid for it by sending a +written explanation to the person you received the work from. If you +received the work on a physical medium, you must return the medium with +your written explanation. The person or entity that provided you with +the defective work may elect to provide a replacement copy in lieu of a +refund. If you received the work electronically, the person or entity +providing it to you may choose to give you a second opportunity to +receive the work electronically in lieu of a refund. If the second copy +is also defective, you may demand a refund in writing without further +opportunities to fix the problem. + +1.F.4. Except for the limited right of replacement or refund set forth +in paragraph 1.F.3, this work is provided to you 'AS-IS' WITH NO OTHER +WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO +WARRANTIES OF MERCHANTIBILITY OR FITNESS FOR ANY PURPOSE. + +1.F.5. Some states do not allow disclaimers of certain implied +warranties or the exclusion or limitation of certain types of damages. +If any disclaimer or limitation set forth in this agreement violates the +law of the state applicable to this agreement, the agreement shall be +interpreted to make the maximum disclaimer or limitation permitted by +the applicable state law. The invalidity or unenforceability of any +provision of this agreement shall not void the remaining provisions. + +1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the +trademark owner, any agent or employee of the Foundation, anyone +providing copies of Project Gutenberg-tm electronic works in accordance +with this agreement, and any volunteers associated with the production, +promotion and distribution of Project Gutenberg-tm electronic works, +harmless from all liability, costs and expenses, including legal fees, +that arise directly or indirectly from any of the following which you do +or cause to occur: (a) distribution of this or any Project Gutenberg-tm +work, (b) alteration, modification, or additions or deletions to any +Project Gutenberg-tm work, and (c) any Defect you cause. + + +Section 2. Information about the Mission of Project Gutenberg-tm + +Project Gutenberg-tm is synonymous with the free distribution of +electronic works in formats readable by the widest variety of computers +including obsolete, old, middle-aged and new computers. It exists +because of the efforts of hundreds of volunteers and donations from +people in all walks of life. + +Volunteers and financial support to provide volunteers with the +assistance they need are critical to reaching Project Gutenberg-tm's +goals and ensuring that the Project Gutenberg-tm collection will +remain freely available for generations to come. In 2001, the Project +Gutenberg Literary Archive Foundation was created to provide a secure +and permanent future for Project Gutenberg-tm and future generations. +To learn more about the Project Gutenberg Literary Archive Foundation +and how your efforts and donations can help, see Sections 3 and 4 +and the Foundation web page at https://www.pglaf.org. + + +Section 3. Information about the Project Gutenberg Literary Archive +Foundation + +The Project Gutenberg Literary Archive Foundation is a non profit +501(c)(3) educational corporation organized under the laws of the +state of Mississippi and granted tax exempt status by the Internal +Revenue Service. The Foundation's EIN or federal tax identification +number is 64-6221541. Its 501(c)(3) letter is posted at +https://pglaf.org/fundraising. Contributions to the Project Gutenberg +Literary Archive Foundation are tax deductible to the full extent +permitted by U.S. federal laws and your state's laws. + +The Foundation's principal office is located at 4557 Melan Dr. S. +Fairbanks, AK, 99712., but its volunteers and employees are scattered +throughout numerous locations. Its business office is located at +809 North 1500 West, Salt Lake City, UT 84116, (801) 596-1887, email +business@pglaf.org. Email contact links and up to date contact +information can be found at the Foundation's web site and official +page at https://pglaf.org + +For additional contact information: + Dr. Gregory B. Newby + Chief Executive and Director + gbnewby@pglaf.org + + +Section 4. Information about Donations to the Project Gutenberg +Literary Archive Foundation + +Project Gutenberg-tm depends upon and cannot survive without wide +spread public support and donations to carry out its mission of +increasing the number of public domain and licensed works that can be +freely distributed in machine readable form accessible by the widest +array of equipment including outdated equipment. Many small donations +($1 to $5,000) are particularly important to maintaining tax exempt +status with the IRS. + +The Foundation is committed to complying with the laws regulating +charities and charitable donations in all 50 states of the United +States. Compliance requirements are not uniform and it takes a +considerable effort, much paperwork and many fees to meet and keep up +with these requirements. We do not solicit donations in locations +where we have not received written confirmation of compliance. To +SEND DONATIONS or determine the status of compliance for any +particular state visit https://pglaf.org + +While we cannot and do not solicit contributions from states where we +have not met the solicitation requirements, we know of no prohibition +against accepting unsolicited donations from donors in such states who +approach us with offers to donate. + +International donations are gratefully accepted, but we cannot make +any statements concerning tax treatment of donations received from +outside the United States. U.S. laws alone swamp our small staff. + +Please check the Project Gutenberg Web pages for current donation +methods and addresses. Donations are accepted in a number of other +ways including including checks, online payments and credit card +donations. To donate, please visit: https://pglaf.org/donate + + +Section 5. General Information About Project Gutenberg-tm electronic +works. + +Professor Michael S. Hart was the originator of the Project Gutenberg-tm +concept of a library of electronic works that could be freely shared +with anyone. For thirty years, he produced and distributed Project +Gutenberg-tm eBooks with only a loose network of volunteer support. + + +Project Gutenberg-tm eBooks are often created from several printed +editions, all of which are confirmed as Public Domain in the U.S. +unless a copyright notice is included. Thus, we do not necessarily +keep eBooks in compliance with any particular paper edition. + + +Most people start at our Web site which has the main PG search facility: + + https://www.gutenberg.org + +This Web site includes information about Project Gutenberg-tm, +including how to make donations to the Project Gutenberg Literary +Archive Foundation, how to help produce our new eBooks, and how to +subscribe to our email newsletter to hear about new eBooks. |