B I R 



B I R 



peroneal tnufcles, and pafies fuperficiallr Over the joint at 

 the heel, and along the oiufide of the metatarfiis : near the 

 pcUex, or great toe, it fends a brarch round tlie back of the 

 leg, to communicate with the tibial vein ; after which, it 

 is continued upon the outlide of the external toe to the es- 

 trenr.ity, receiving anaftomofing branches frum thi tibial 

 vein. 



Where the veins nin fuperficially upon the upper and 

 lower extremities, thty feem to fupply the place of the 

 branches of the cephalic, hcjilic, and the two faphem ; but 

 the analogy is loll upon the upper arm and thigh : thefe 

 branches forming deep-feated trunks : this confiitutes the 

 greateft peculiarity in the diftribution of the v;.ins ia the 

 extremities of birds. 



KUnii'S. 

 Thefe organs occupy the pofterior part of the common 

 cavity of birds, from the lait rib to near the coxygeal ver- 

 tebrje ; they fill all the cavities and deprcfilons of the bones 

 of the pelvis ; the pofterior furface, therefore, of the kid- 

 nies is extremely irregular ; their rinterior part is rather 

 flat, and they are notched upon the external edge, which 

 gives ufually the appearance of their being compofed of 

 three lobes . but the ineqealities of the edge, feem to 

 arife rather from the kidnies being larger at one place than 

 at another, than from an original diviiion into lobes : the 

 prominences correfpond to the moll depreffcd parts on the 

 pelvis ; accordingly, the kidnies are obferved to form a 

 projeclion at tht upper end, where they lye on the depref- 

 Con of the ofTa ilia, again oppofite to the hollow on the 

 infide of the ifcihadic foramen, and laflly, at the lower 

 part of the kidney, where it fills the concavity of the 

 ifchium. 



The kidnies have a covering of thin peritoneum, and 

 under this, they feem to poffefs another thin membranous 

 tunic, which clofcly inverts them, as well where they are 

 applied to the bones,~as anteriorly ; this coat alfo appears to 

 be reflefted into the fubftance ot the kidnies, ard to form 

 the cellular conneftions of the difierent parts which com- 

 pofe ttefe organs. According to the academicians, the 

 kidnies of the tormonzn/ are feparated from ilie other parts 

 of the lower belly, by a diftincl membrane, and inftead of 

 being divided into three lobes, are toothed like a cock's 

 comb on their gibbous part. 



The texture of the kidnies is very fragile ; readily giving 

 way under the flighted injun-. They yield to the prcf- 

 fure of the finger a granular feel, as if compofed of a 

 number of minute bodies, eafily feparable from each other : 

 the furface of the kidnies, alfo, prefents the appearance of 

 an aggregation of fmall glands. 



The trunks and larger branches of the bloodvtfkis of 

 the kidnies have been already defcribed. The termination 

 of the minute ramifications of the artery car.not be fo 

 clearly perceived as in mammalia. When coloured fluids 

 are thrown in by the artery, the whole fiibflance of the 

 kidney appears to equally admit the injeftion : the minute 

 branches of the blood-veffcls are too numerous, therefore, 

 to allow of a dillindl view of the figure afTum.ed by the 

 fecretory extremity of the artery ; but it is probable, 

 from the llrurture of the kidney differing in other circum- 

 ftances, that it is not wound into a coil, as in man and 

 quadrupeds. 



The kidnies of bird=, in general, do not poffefs any 

 cavity for collecling the urine, previous to its expulCon by 

 the excretory dudl : each of tlie little malTcs which form 

 the original glands, produces a du£t ; thefe are joined by 

 the neighbouring ducts, and thus others are generated, 

 which terminate in the ureUr or common excretory du£l of 



each kidney. The ureter lies upon the anterior furface of 

 the kidney, partially embedded in its fubilance, fo that 

 it is vifible along the whole gland, except at the upper 

 part. 



The members of the academy defcribe the kidnies of the 

 q/lric/} as being evidently compofed of d^ftinft glands, and 

 that the ureter did not lie as in other birds, fuperficially, 

 but was concealed in the glandular fu';>ilarce ; in whic^ 

 Ctuation it fuffcred a degree of dii t ation, fornrung as it were, 

 a pc'.-vb, the whole length of t!ic kidney, into which the 

 different excretory ducts difcharged their ccntcnls ; not, 

 however, from pap'.Us-, as in mammalia, but by open and 

 plain orifices. Mr. Ranby, in his account of the anatomy of 

 the ojlrtch, dates, that he found the ureters occupy their 

 ufual fituation on th.e nr.iddle line of the anterior furface of 

 the kidney ; but that the fuperior branch of the ureter was 

 very confpicuous, and entered the middle of the kidney, 

 where it formed a very large pelvis. 



The dr'j(Elure of the ureters appears to be exaftly tlie 

 fame which thefe duels poffefs in the human fubjeft. 



The courfe of the ureters, after leavuig the kidnies, is 

 behind the reclum, to which they become conneclcd by the 

 peritoneum covering the inteiliue : they proceed, for a very 

 little way, involved in the coats of the back of the rcflura, 

 and open ufually upon two httle papilla, which projeft into 

 the cloaca, or termination of the rectum.. The orifices of 

 the ureters in the cloaca, are much lefs than the width of 

 tubes to which they belong ; this, therefore, added to the 

 obliquity with v.-hich they perforate the cloaca, an- 

 fwcrs all the purpofes of a valve, and prevents any regurgi- 

 tation of the urine back upon the kidnies. 



The parifian dificftors obfer\'ed in the cajfotvary and 

 riemoifelle oi Numiilia {ardea virgo), that the ureters became 

 united to the excreto'-y du£"t of the tellicle, at the lower 

 part of ths kidney ; the common duil produced by their 

 union terminated, as ufual, in the back of the cloaca. 

 This ftruiSure certainly does not exid in the generality of 

 birds. 



The above defcription anticipates the obfervatior, that 

 birds are unprovided with any didinft reftrvoir for urine ; 

 analogous to the bladdn- : it is the cafe throughout the 

 whole clafs, without an exception, that the faeces and 

 urine are expelled together ; but the dilatation of the end 

 of the reclum or cloaca, in fome fpecies, fupplies the want 

 of the urinary bladder in a great degree, and renders the 

 ejections of both the urine and fxces lefs frequent than 

 they would otherwife be, by alTording a temporary accom- 

 modation to a confiderable quantity of oxrement. Thefe 

 dilatations are remarkably large in the oftr'uh, parrot, l3c. 

 See that part of the article which treats of the great intef- 

 tine of birds. 



It is a matter of common obfervation, that the excre- 

 ments of birds are of a white colour, and appear as if they 

 contained fome cretaceous fubdanccs : this cffcCl is univer- 

 fally attributed to an admixture with the urine, which is 

 fiippofed to be of this colour and confidence ; it deferves to 

 be mentioned, however, that if the urine be expreiTed from 

 the kidnic ■, or examined before it has paffcd into the retlum, 

 it is neither white, nor of a chaiky co:.Cdcnce, but a 

 li.iipid aqueous fluid, which exhales an u'lnous fmell, that 

 is very perceptible in the larger bii-ds, from which fome . 

 quantity of the urine may be obtaiiied, by comprcffinnr the 

 kidnies. It would feem more probable, that the white 

 and chalky appearance of the excrements of birds, depended 

 Upon the quantity of calcareous m.atter contained in the 

 foiid parts of the faeces, than that it is derived from the 

 uriue. In proof of this fuppofilion, it may be remarked, 



that 



