B I R 



mentous fubRance, which fiipplics tlie place of tlie corpora 

 ea-vernofa, but does not fecm to contain any cells or cavity 

 internally. 



There is a groove, correfpoiiding to the urethra, along 

 the fide of the white ligament ; it takes the fpiral ccurfe of 

 the penis, and in no inftance conld we difcover that it 

 formed a diftiiift canal, the external coat of the penis appear- 

 ing always to dip into the groove, fo that it was vifible ex- 

 ternally ; and hence it might bo faid that the urethra oihnis 

 is iituated upon the outfide of the penis. See P/ateVll, in 

 the yluntoniy of Birds, Fig. 3. reprefents thefe parts as they 

 are found in the gander ; a the penis, fhaped like a fcrew, 

 with the edges denticulated or notched by the folding of the 

 external coat ; bb the urethra commencing upon the left fide 

 of the penis, and continued upon the fame fide around the 

 fpire or fcrew ; and at the end of the penis the fulcus gra- 

 dually difappears. 



The form of the ojlrich's penis is not fpiral ; it is alfo 

 fmooth upon the furfacv, and in fhape it has been likened to 

 a calf's tongue. The Parifian anatomifts deferibe it as being 

 compofcd of white thick membranes, and of two ftrong 

 hard ligamentous fubftances. They appeared to confid of 

 very compaft tranfverfe fibres ; one ot the membranes was 

 thicker than the other, and afforded a covering to the penis ; 

 the other enveloped immediately each of the two ligaments, 

 which were feparated from each other, and united about two 

 fingers from the extremity. One was longer than the other, 

 and meafured two inches. The origin of the penis was at 

 the cartilaginous fwelling, which is fituated at the junftion 

 of the bones of the pubis ; from thence it was turned down- 

 ward, and contained in a little pouch, which was placed at 

 the lower part of the cloaca, in which the penis was continued 

 to the anus. This fmall pouch can be diftinftly feparated 

 from the large bag of the cloaca, by the contraftion of the 

 margin of its foramen. The lefier pouch only permits the 

 excrements to pafs from the other occafionally, and when 

 it is clofed, forms a fort of flieath for the penis. 



The penis of birds receives fome diftindl mufcular fafciculi 

 from the reftum, which are inferted into the root of the liga- 

 mentous body; they appear to have the power of retraft- 

 ing it, or rolling it into the fpiral form, and may perhaps 

 render it more fteady during coition. 



The mufcles of the penis are large in the ojlrich. The 

 academicians deferibe four of them, two on each fide. The 

 two firft took their origin from the internal part of the os 

 facrum, and defctnded along the pouch of the rcftum, for 

 the fpace of two lines, which they penetrated near the ex- 

 tremity, and pafiing under the fphinfter ani, were inferted 

 at the bafe of the penis. The two other mufcles went from 

 the internal part of the os ilium towards the bottom of the 

 kidnies, and dcfccnded by the fides of the ureters, and alter 

 perforating the reftum, were attached to the Lteral parts 

 of the pen!P. 



The penis of birds is unfurniflied with any flrufture finii- 

 lar to \X\i glans o\- prepuee ; from which it might be queftioned 

 whether it is capable of receiving any peculiar fenfations 

 duiing the aft of copulation. It would feem probable, 

 however, that the penis is the chief feat of pleafure in birds 

 as well as mammalia, becaufe it changes its form during 

 coition, and experiences a great degree of relaxation after- 

 wards. The penis of the drake is protruded fome inches 

 oiit of the anus during the performance of the venereal aft; 

 and after the orgafm is concluded, it is fo much relaxed, 

 that the animal has not the power of retraining it for fome 

 minutes ; in which condition the penis hangs from the anus, 

 and fo much refemblcs an earthworm, that the ducks mif- 

 take it for one, and attempt to fwallow it. It is remarkable, 



Vol. IV, 



B I R 



however, that the greater number of birds are either ui'.pro- 

 vided with a penis, or have merely a rudiment of it, which 

 is incapable of condufting the femen into the organs of the 

 female. 



In thofe birds which want the penis, it is very eafy to per- 

 ceive the manner in which the vafa deferentia term.inate : 

 thus, in the common cock they can be readily traced paf- 

 fing along the fides of the ureters to the back of the cloaca, 

 into which they open a little lower than the ureters upon 

 two papilla", which are elevated upon a ridge formed by the 

 internal coat of the inteftine, jull within the verge of the 

 anus. Thefe papillae are prominent and fharp pointed ; and 

 although the diifts are of fom.e fize immediately behind, the 

 aperture on the point of the papillx is fo extremely fmall, 

 that it is difcovered with difiiculty, and will fcarcely fuffer 

 the fined briftle to pafs through it. See PlateWl. in the 

 Anatomy of Birds, fg.2.; cc the two (harp papillae, upon 

 the points of which the vafa deferentia term.inate in the cot^. 

 A briftle is introdu.ced into one of them, and above them, 

 and nearer the centre of the inteftine are feen the orifices of 

 the ureters defignated by the letters d d. 



As thefe birds have no means of conveying the femen 

 into the body of the female, a mutual everfion of the ex- 

 tremity of the inteftine always takes place during the copu- 

 lation of fowl. 



The termination of the excretory dufts of the tefticlc are 

 difficult to difcover in moft of the birds which are furniflied 

 with a penis. This arifes partly from the coats of the dufts 

 becoming extremely thin and dehcate near the extremity, 

 and partly from the papillx upon which they open into the 

 gut being in thofe cafes fo fmalLis ver)' eafily to tfcapc ob- 

 fervation. 



The academicians did not fuccecd in tracing the vafa 

 deferentia to their termination in any of the birds they dif- 

 fefted. They relate, however, that the penis of the rjjlrich 

 and cnJfo<wary had no communication with the dufts, nor did 

 they contain any tube in the internal part by which they 

 could give pafTage to the femen. In all the birds we have 

 examined, we could not perceive the leall appearance of a 

 canal in the interior part of the penis, or any means of com- 

 munication between it and the vafa deferentia. 



In \}at gander we have been able to difcover the mode in 

 which the femen is difcharged from the excretory dufts. 

 At fomediftance behind the root of the penis there are twopa- 

 pillve, furrounded by a number of fmall follicular glands; they 

 are not fo far afunder as thofe of the coch, and fo little promi- 

 nent, that unlefs minutely examined, they are not diftinguifti- 

 able from the glandular part? of the furface of the inteftine 

 which lie next them, and might eafily bemiftaken for a promi- 

 nent edge of one of the follicles : from the point of thefe pa- 

 pills adutt can be traced, as m\}c\i.cock, to the back of the in- 

 teftine ; but furniflied with coats fo thin that it is perfectly 

 tranfparent. See PlateNYi. in the Anatomy of Birds, Jig. ^. 

 cc the fmall papillx on which the vafa deferentia terminate 

 in ihe gander. Some fmall follicular glands are feen around 

 them, and farther within the inteftine the ureters open, as 

 indicated by the letters dd ; at thefe points alfo there are 

 fome fmall mucous glands. 



Mr. Hrme has defcribed the penis of the drake as pofTef- 

 fing a diftinft canal analogous to the urctlira of mammalia, 

 into which the vafa deferentia enter clofe to its origin at the 

 verge of the anus. He ftates the penis to meafure, when 

 pulled out to its full extent, fix inches long, but that when 

 left to itfelf it difappears within the verge of the anus, in 

 co'.ifcquence of the conlraftile power of the urethra. (See 

 Phil. Tranfaft. vol.xcii. p. 361.) The reprefentation of 

 the penis of the drake h copied in PLitcVll. of the Ar.atoniy 

 3H Hf 



