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TEXTBOOK OF ZOOLOGY 



are much shorter in animals producing only a few ova than in 

 animals producing many. 



Certain similarities, however, are evident in the urinogenital sys- 

 tem of reptiles and of lower forms. The urinogenital products are 

 voided into the common cloacal chamber as in lower animals. 



The kidneys of the horned lizard are reddish brown, paired bodies 

 lying on each side of the middorsal line, between the large intestine 

 and the body wall. Technically they are outside of the body cavity 

 since they are dorsal to the peritoneum. Each kidney has a delicate 

 excretory duct, the ureter. In the males this duct opens into the 



Oviduct — 



Apertures 

 oviduct 

 and ureter 



-Intestine 



J4} Kidney 



%M Ant. cloaca 



M^ Cut oviduct 



'^M' Ureter 



r Post.Cloaca 



^ Anus 



Fig. 299. — Urinogenital system of female horned lizard from ventral view. 



vas deferens and a common duct leads to the cloaca. In the females 

 the ureter connects the posterior end of the kidney with the dorsal 

 wall of the cloaca. 



The male reproductive organs consist of a pair of testes, a pair of 

 eversible hemipenes, and various connecting ducts. The testes are 

 white oval bodies lying in the posterior part of the body cavity, one 

 on each side of the mesorectum. Each testis is attached to the dorsal 

 body wall by a sheet of peritoneum, the mesorchium. The series of 

 ducts connecting each testis with the cloaca includes the rete testis, 

 the epididymis, and the vas deferens in order. The vas deferens 

 passes posteriorly, joins the ureter, and enters the cloacal wall. 

 The paired, eversible hemipenes, or copulatory organs, are vascular 



