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PRINCIPLES OF ANIMAL lilOLOGY 



system. In the female, the funnel of the oviduct is very near the ovary, 

 but is not connected with it. The oviduct opens into the uterus in which 

 the young are retained and nourished until birth. The form of the uterus 

 differs in the different groups of mammals. That illustrated in Fig. 99 

 is common among the carnivores, rodents, and others which bring 



Fig. 98. — Urinogenital system of male frog, diagrammatic. The kidney at the left 

 is in surface view, at the right in diagrammatic optical section. A, anus; BT, Bidder's 

 tube; CL, cloaca; CT, connecting tubule; CV, postcaval vein; FB, fat bodies; K, kidney; 

 LI, large intestine; MD, Muellerian duct;<S/, small intestine; T, testes; UB, urinary bladder; 

 UR, ureter; VE, vasa efferentia. 



forth young in litters. The uterus is connected to the exterior by the 

 vagina which is the copulation passage. The urinary bladder, which 

 belongs to the excretory system, is connected to the lower portion of the 

 vagina by means of the urethra. In some mammals there are accessory 

 glands in connection with the female urinogenital system. In the male, 



