580 



URINARY APPARATUS. 



Solipeds. In them, this cavity is very large, and at the base of the crest shows deep diverticuli 

 that iMmity in the substance of the kidnev. 



The kidneys of the Pig are simple externally, and voluminous; the hilus gives access to 

 a cavity in which are a number of papillae collected in twos or threes, and covered by calices. 

 The calices and the ureter have tiie same arrangement as in the Ox. (There are 10 or 12 

 papillse, and as many calices.) 



2. Bladder.— The most important difference in the bladder of the domesticated animals, 

 consists in the extent of development of its peritoneal envelope. In nonsoliped animals this 

 covers all the organ to the neck ; the ligaments are also very short, and the viscus may be 

 easily projected into the abdominal cavity. The bladder is thin, and of considerable capacity 

 in Ruminants and the Pig ; in tJie Dog, on the contrary, it has a very thick muscular 

 layer, its fibres forming distinct fasciculi, especially when in a state of retraction. (In 

 Ruminants, the orifices of the ureters are near each other; at the fundus the mucous 

 membrane shows a small fossa, which is continued by a narrow canal that terminates in a 



Fig. 345. 



Fig. 346. 



Fig. 347. 



KIDNEYS OF THE OX. 



Fig. 345. — Right kidney, viewed on its upper and external face. Fig. 346. — Left kidney, from its 

 internal and inferior face: a, Pelvis; b, b, b, branches of the pelvis terminating in calices; c, 

 ureter; (i, renal artery. Fig. 347. — The calices in the left kidney. The contents of the hilus, 

 including the branches of the pelvis, have been removed to show the tubercles at the bottom of 

 these calices. Only seven are visible, the others being beneath the borders of the renal fissure. 



cnl-de-sac, and constitutes a free appendix about half an inch long, and of the thickness of a 

 goose-quill). 



3. Supra-renal capsules. — These small organs are discoid in the Sheep and Pig, reniform 

 in the Dog. In the Ox, they are situated at a certain distance in front of the kidneys, and 

 their shape is like that of these bodies in the Horse ; though they are a little constricte i in 

 the middle, and slightly curved. 



In Birds, the kidneys " are lodged at the same height, behind the peritoneum, imme- 

 diately pdsterior to the lungs, and in the lumbar and pelvic regions, where they occupy several 

 fossae excavated in the upper face of the pelvis. Their form is irregular and more or less 

 elongated, depending upon the hemes and other parts to which they are applied, and on which 

 they are moulded. In many Birds, nevertheless, three portions, more or less separated by 



