116 Mammalia. Urinary Organs. 



were a multiplication of simple kidneys ; in some species they 

 continue in this form during the whole of life : this is par- 

 ticularly the case in those that live in water. When a 

 kidney, is thus subdivided, each ' venule ' has its oion excretory 

 duct. The Ureters almost invariably terminate in a Urinary 

 bladder, and have an oblique valvular course through its 

 coats. The Bladder appears to be smaller in those species 

 that feed on flesh than in those that feed on herbs. 



URINARY ORGANS (Special). 



1. Lohdes. 



Sector ialia. In the Phocida) (Pinni-gr.) the kidney is divided 

 into from seventy to one hundred or more lobules, and its surface 

 has in consequence a tesselated aspect. 



Cete. The kidneys have a racemiform appearance ; in the 

 Dolphins two hundred separate lobules can be counted. 



2. Papillcd. 



The following Species generally have only a single papilla into 

 wliich all the renal tubuli open, viz.: 



all Catarrhine Quadrumana : and most Hodentia, Sectorialiaf In- 

 Enamellata, and Monotremata. 



3. Termination of Ureters. 



In the Monotremata the ureters do not terminate in the bladder^ 

 but in the urogenital canal; the orifice of the sperm duct, or oviduct, 

 intervening between that of the ureter and the bladder. The urine 

 may dribble out with the faeces, or may pass by a retrograde course 

 into the bladder ; but in either case it is expelled ^er cloacam^ not 

 per urethram. 

 4. Superficial ramijications of veins, Sfc. 



In most Bigitigrade Sectorialia (Felidae, Hya^nidae, Yiverridae, and 

 Suricate), the kidney is remarkable for the arlorescetit disposition of 

 the veins on or near the surface. In Pkoca (Pinni-gr.) the veins 

 unite to form a netivork on the surface of the kidney. 



