70 GENERAL BIOLOGY. 



In the male : 



1. The testes : two long, white, lobecl bodies 



which extend posteriorly into the abdomen 



and are connected near their anterior ends 



by a transverse commissure. 

 Near the middle of each testis a vas deferens 



arises and passes ventrally to the genital 



opening (A. IV. 4. (>).) 



By cutting through the muscles, etc., at the side, 

 folloiv the vas deferens of one side from the testis 

 to the external opening. 

 In the female : 



2. The ovaries : elongated, yellowish bodies con- 



tinued posteriorly into the abdomen, with 

 the oviduct passing to the genital opening 

 (A. IV. 4. (a)). 

 Trace the oviduct from the ovary to the external 



opening. 



Diagram of reproductive organs and ducts ! 

 III. Digestive System. 



In the median line anterior to the region of 

 the heart : 



1. The stomach a dilatation of the alimentary 



canal. 



Insert the handle of a section-lifter through the 

 mouth-opening into the stomach. Turn the stomach 

 to one side to see : 



2. The oesophagus : a short vertical tube from 



mouth to stomach. 



