B I R 



B I R 



Plate VTI. of the ytnatowy of Birds. Fig. 5. exliibits the flocculi, which give the internal part of the utenj! the ap- 



genital organs of the hen during the feafon for layin-j eggs ; 

 at the fiipcrior part is feen the ovary, or rncemus o-vorum, or 

 vtltHartum. The ov^ are arranged according to their Hate 

 of growth. The iargell are moll external and pendent from 

 their footilalks ; thofc lefs advanced are clofe upon the ma- 

 trix or bafis of the ovary ; many of them are as yet but im- 

 perfeft rudiments of the ova, and appear but as white 

 fptcks in the matrix. The capfules of the ova, near matu 



rity, difplay a very beautiful and luxuriant diftribution of far into the cavity of the tube, 



pearance of being fringed or foHated. 



Tiie tube again becomes diminidied in capacity, arid its 

 ftruclure changed, to form the portion confidered analogous 

 to the vagina. At the origin of this part from the oval di- 

 latation there are feveral anriular contrac\iona ; after which, 

 the canal undergoes fome degree of convolution, which is 

 concealed by the peritoneal coat. The internal membrane 

 produces longitudinal ruga, or folds, which do not projetl 



blood- v^iTtls upon every part of their furface, except where 

 the ova are to come out ; n a point out the ftripe on the 

 anterior part of each capfule, which n devoid of blood vef- 

 feK ; b a capfule which has flud its ovum, exhibiting the 

 appearance of a cup or calyx. 



The ovarian tube, or ovirliicl, during the feafon of laying, 

 fills the greater part of the lower belly ; it forms a number 

 of curves or convolutions fimilar to the inteftines, which, 

 however, are not permitted the fame latitude of motion 

 amongft each other, becaufe the prolongation of peritoneum, 

 vhich includes the oviduft, is remarkably ttrong, and is not 

 fo long as the pnrts it contains, and therefore the convolu- 

 tions are ceiled clofe tog-nher, and even fome of them are 

 doubled up within the ptritoneum. The difproportion be- 

 tween the ovidurt and pvriioneum, which invefts it, arifes 

 from the additional bulk the ovary acquires when its func- 

 tions are exercifed, whilll the peritoneum mull prrferve at 

 its back part its original extent, i. e. the length of the left 

 kidney, from the middle of which it is refiefted. 



There is no decided mufcular coit belonging to the 

 oviduft ; there are, however, mufctslar libres between the 

 peritoneal and internal coats of thofe parts, which have re- 

 ceived the names of uttrus and vagina ; upon the former 

 they are tranfverfe, and upon the vagina the courfc of the 

 fibres appears to be longitudinal. 



The internal coat of the oviduft is the mod remark- 

 able part of its flrufture ; and upon it chiefly depends 

 the diftinftions which have been made of the tube i:;to 

 injimdihulum, Fallopinn lube, vlerus, and •vngtna. 



The infur.dibulum is the extreme part of the tube next the 

 ovary ; it is compofed apparently of a hngle thin mem- 

 brane ; the peritorieum and the internal tunic becominf 

 both delicately fine, and fo clofely united to each other, 

 at this place, that they feem to be but one. This mem- 

 brane is expanded beneath the ovarv in a loofe manner, 

 like the iolds of a garment, and is faftened by its fuperior 

 edge to the bafis or matrix of the ovary ; and inferiorly it 

 is connefled to the uterus : by which means the folds of 

 the membrane are always kept fpread out, ready to catch 

 the ova as they are difcharged from the racemus or vitella- 



The oviduct finally opens into the cloaca on the left fide, 

 not by a fimple aperture, but the extremity of the vagina 

 is protruded for fome way into the cavity of the inteftine, 

 appearing as if a portion of the oviducl were turned infidc 

 out ; and to the puckered foramen thus produced, the older 

 anatomiils, who were always defirous of comparing the 

 ftrudlure of other animals with that of the human fubjeft, 

 gave the name of vulva. See Plate VII, in the Anatomy of 

 Birds, Jig. ^.-j ccc the membranous expanfion of the ovi- 

 AviGt, d d ha attachments to tiie ovary and the uterus, e the 

 aperture leading from the infundibulum to the interior of 

 the oviduct ; fffff the convoluted part of the oviduft, 

 which is fuppofcd to be analogous to the FaHopiau tube, 

 and a part of it laid open to Exhibit the fpiral folds of the 

 internal membrane; A/j the oval cavity or uterus cut open, 

 and a portion of it turned backward to expofe the fohated 

 flrufture of the internal membrane ; ii the vagina detached 

 in a degree from its peritoneal covering to bring it more into 

 view ; /: the cavity expofed, (hewing tiie longitudinal folds; 

 / the projeftion of the end of the oviduft into the cloaca, 

 with the corrugated foramen by which it opens into the 

 gut ; m a portion of the reftum, left to explain the connec- 

 tion thcfe parts have to each other; nn the ureters, through 

 which a brillle is introduced. 



The ufes which the fevtral parts of the oviduA of birds 

 ferve, are very peculiar, and can hardly be compared with 

 the funftions of the genital organs of other animals. When 

 the ovum is fhed from the viteilarium, it is but imperfectly 

 formed ; and in palling along that portion of the ovidudl 

 which has been called the Fallopian tube, it meets with an 

 albuminous fluid, which is fccreted in abundance from the 

 plicated membrane ; a certain quantity of this fluid attaches 

 itfelf to the ovum, and coniiitutes the whites and the chala- 

 zes. The egg now afl'unics an oval figure, and while ftill 

 foft, defcends into the dilated part of the oviduft, in which 

 it is detained for fome time, and obtains the calcareous co- 

 vering or (lifl! ; after which, the lower portion of the dud, 

 or the vagina, fuffers itfelf to be enlarged, and the egg is 

 expelled from the body of the bird. For the further hiftoiy 

 of the formation of the ovum, we refer the reader to the arti- 



rium. The pafFage from the membranous expanfion of cle Egg. In birds, and all animals ftriftly oviparous, the 



the tube into the oviduft is contrafted, and thence occurs 

 the iimilitude of this part to a funnel, and the application 

 of the term infundiLulum. 



The next portion of the oviduft, or Fallopian tube, is of 

 conliderabie length, being feveral times coiled backwards 

 and forwards upon itfelf. It is very nearly of the fame 

 width at every part ; and the inner membrane is fingularly 

 foft, and forms numprous thick folds, which take an oblique 



evolution of the embryo, and the growth of the fcctus, is car- 

 ried OH without the body of the parent, and therefore the 

 funftions of the organs of generations in thefc animals are 

 confined to the developement and perfeftion of the ovum, 

 wliich, as already obferved, is partly accompliflied in birds, 

 while the egg remains in the ovary, and partly while it tra- 

 rerfes the ovarian tube. It therefore feems improper to 

 borrow the terms applied to the organs of viviparous ani- 



or fpiral courfe. The internal furface of this part of the nials in the defcription of thofe which only miniftcr to the 



tube relembles very much that of the digeftive llomach in 

 ruminating animals. 



Where the part termed the uterus commences, there is a 

 contraftion of the tube, to which fucceeds a dilatation of an 

 eval or egg fhape ; in this the internal membrane acquires 



formation and fupport of the ova. The progrefs of the foe- 

 tus in birds ; its mode of exiftence while in the egg, and 

 the provifions for its fubfilltnce afterwards, will be treated 

 of under the head of INCl;BJ^T^ON, which fee. 



It is not eafy to determine how far the male femcn is con- 



more firmnefs, and inftead of the foft white fpiral plicce, veyed into the organs of birds during copulation. The older 

 produces an immenfe number of ftrong vafcular proceil'es or anatomiils afferted, that the two papLllie on which the vafa 



3 H 2 defereutia 



