738 



AVES. 



are lodged in deep depressions, situated on each side of the spine, in the 

 lumbar and pelvic regions, their posterior aspects being moulded into 

 all the cavities formed by the bones in that situation. In their essential 

 structure each kidney is made up of innumerable microscopic flexuous 

 tubes, which, joining again and again into larger and still larger trunks, 

 ultimately terminate in the ureter, without the interposition of any 

 infundibular cavity analogous to the pelvis of the human kidney. 



Fig. 368. 



Generative organs of the Cock. 



(2092.) From tne manner in which the kidneys are imbedded, the 

 ureters are necessarily derived from their anterior aspect. After re- 

 ceiving all the terminations of the urinary tubules, they pass behind the 

 rectum to the cloaca, into which they discharge the urinary secretion. 

 The cloaca, therefore, receives the terminations of the rectum, of the 



