172 VERTEBRATE ZOOLOGY 



Exercise 9. Make a semidiagrammatic drawing of the opened glandu- 

 lar stomach, gizzard, and duodenum, showing these features. 



Cut the rectum and remove the digestive tract from the body. 



The Urogenital System. The urinary system consists of a pair 

 of kidneys, a pair of ureters, and the cloaca. Each kidney is made 

 up of three lobes, which lie close against the dorsal body wall in 

 the posterior part of the body cavity ; the peritoneum passes over 

 their ventral surface. Do not remove them. The ureters are a 

 pair of slender tubes, each of which emerges from the hinder 

 border of the anterior lobe of the kidney and passes along the 

 ventral surface of the two posterior lobes, directly back to the 

 dorsal wall of the cloaca. 



Lying on the ventral surface of each kidney is a small yellowish 

 organ, — the suprarenal, or adrenal, body. 



The Genital System; the Male. The testes are a pair of white, 

 ovoid bodies which lie against the medial borders of the anterior 

 lobes of the kidneys. Note the mesenterial fold which attaches 

 each to the dorsal body wall. They are joined with the cloaca by 

 the vasa def erentia, a pair of convoluted, slender tubes which pass 

 posteriorly from the medial border of the testes along the ventral 

 surface of the kidneys. They lie lateral to the ureters. The hinder 

 end of each is dilated, forming a vesicula seminalis. 



The Female. But one ovary and oviduct are present, the left 

 ones ; those on the right side are present, however, in the embryo. 

 The ovary is a granular organ which lies against the medial border 

 of the anterior lobe of the left kidney, attached to it by a mesen- 

 terial fold ; yellow ova of various sizes will usually be seen in it. 

 The oviduct is a wide tube, with thin walls anteriorly and thick 

 walls posteriorly, which extends, suspended in a mesenterial fold, 

 along the ventral surface of the left kidney and the dorsal body 

 wall to the cloaca. Its anterior end opens into the body cavity by 

 a much elongated, funnel-shaped orifice into which the ova pass 

 when they escape from the ovary. A rudiment of the right oviduct 

 is present in the form of a slender tube extending a short distance 

 forward from the cloaca. 



The oviduct secretes the white of the egg and the shell, as the 

 ovum passes down it. 



