URINARY SYSTEM OF MAMMALS. 



607 



capsule of the corpuscle, m. 1 In the Rhinoceros the pelvis is re- 

 presented by two longitudinal canals which converge and unite 

 to form the ureter, of which they may be said to be the begin- 

 nings. The kidney is lobu- 



482 



lated, or composed of numer- 

 ous renules, each with its corti- 

 cal and medullary part, but the 

 tubes of the latter unite and con- 

 verge to open into the longitu- 

 dinal, quasi pelvic, canals with- 

 out any valvular prominence.' 2 

 The kidney of the Elephant 

 differs chiefly in the termina- 

 tion of the tubuli of the lobes 

 upon slight prominences ; of 

 these there is no appearance 

 in the Equidce. The tubular 

 divisions of the pelvis are 

 shorter in the Zebra than in 

 the Horse or Ass, where they 

 are continued nearer to the 

 upper and lower ends of the 

 kidneys. The ureters in these, 

 as in the Tapir, terminate as 

 usual in the neck of the blad- 

 der. But in Hyrax, conco- 

 mitantly with an unusual length of loins, the ureters do not 

 reach so far down, but open obliquely into the back part of the 

 1 fundus vesicae.' 



. In the Hog-tribe the kidney is simple ; but the mammilla is 

 somewhat extended at its free termination. In the Chevrotains 

 and other small ruminants the kidney is simple as in Lissencephala ; 

 but in larger deer and antelopes the beginning of a more complex 

 structure is seen in the aggregation of the tubuli uriniferi into 

 several cones, distinct at their bases, but blending into a common 

 elongate or ridge- like mammilla. This structure also obtains in 

 the Camelida ; but in the Bovidce the cones are distinct, termi- 

 nate by mammillae in tubular productions of the renal pelvis, and 

 are associated with some lobes or divisions of the cortical sub- 

 stance, such divisions sometimes including more than one cone. 



In the Dugong the tubuli terminate in a single pelvis by 

 several lateral ridges ; but the exterior is undivided. In the 

 Manatees, and in Rhytina, according to Steller, the kidney is 

 1 cxxxvu. 2 \". p. 44, pi. 14, figs. 2 and 3. 



Malpiglian tufts and corpuscle : Horse, cxxxvu 



