440 Animal Biology 



and tongue contain organs of taste, especially if foods and chemicals are 

 in solution. Lateral sense organs are present in the tadpole stages only 

 and are stimulated by vibrations of rather low frequency. Adult frogs 

 do not have a lateral line. 



Reproduction. — The sexes are separate (diecious) (Figs. 218 and 219) . 

 The sperm of the male arise in paired, small, oval testes. The sperm pass 

 through the vasa effere?itia into the kidneys ^ then by means of Bidder's 

 canal, into the ureter, thence into the cloaca, and out through the anus. 



Fat body 



Testis 



■^ VQsa effcrentia 



y — Collecting tubules 



Bidders canal 



/drenal cjiand 



Kidney 



Ureter 



Rectum 



h]addQr 



Omdacb 



Cloaca 



Anus 



Fig. 219. — Urinogenital system of male frog (ventral view). On the right, 

 the testis has been moved and the kidney dissected to show the internal tubes. 

 The sperm pass from the testes through the vasa efferentia into Bidder's canal 

 from which they pass out through the ureter. Part of the circulatory system and 

 the adrenal (ductless) glands are also shown. Note the poorly developed rudi- 

 mentary oviduct in the male. 



The eggs arise in the large paired ovaries, and later break out through 

 the walls of the enlarged ovary into the coelom (body cavity) . From the 

 latter the eggs eventually find their way into the much-coiled, paired 

 oviducts, the funnel-shaped openings of which are located near the an- 

 terior edge of the abdominal cavity. The oviducts lead into the thin- 

 walled uterus which leads into the cloaca. The latter leads to the anus. 

 The eggs are given a coat of gelatinous food which is produced by glan- 



