86 



General Biology 



end of the kidneys, while branching masses of a yellow shade are usually 

 attached to them. The sperm, the male gamete ( ), 



is produced in the spermaries, being carried through slender ducts, the 

 vasa efferentia, through the kidney to empty into the ureters. It will 

 be observed, therefore, that in the male frog the ureters serve both as 

 an exit for the excretion of the kidneys and for the secretions of the 

 spermaries. In some species of frogs, the ureters are slightly enlarged 

 to form a small sac just where they enter the cloaca. Such sacs are 



aoJ>. coel.mes. 



f.k. 



neb.tt. 



Fig. 25. The Urogenital Organs of the Frog. A, Male; B, Female. 



ao.b., systemic arteries; ao.c, main aortic trunk; cav.i., vena cava inferior; 

 cl., cloaca (dissected from the ventral side); coel,mes., coeliaco mesenteric artery; 

 d., large intestine; f.k., fat bodies; h.s.l., urogenital duct; h.s.l.', entrance of uro- 

 genital duct into cloaca; il., iliac artery; n., kidney; neb.n., adrenal bodies; ost.abd., 

 funnel-shaped opening of oviduct; ov., ovary; ovid., oviduct; ovidJ ', entrance of 

 oviduct into cloaca; test., testes; ut., uterus; ves., urinary bladder; ves.', opening 

 of bladder into cloaca; ves.sem., seminal vesicle; w., Wolrian duct; w.' , opening of 

 Wolfian ducts. (After W. Meissner.) 



known as seminal vesicles. The sperm are held there until ready to be 

 discharged. 



If the body of a female (B, Fig. 25) be opened in the breeding season 

 the ovaries will be found filled with eggs which seem to fill almost the 

 entire body-cavity. The ovaries, the female gonads ( ), 



are placed in a position corresponding to the spermaries in the male. If 

 it is not the breeding season, the ovaries are rather small, slightly folded 

 and leaf-life, not very much larger than the spermaries, but of a differ- 

 ent shape. The eggs break out of the ovary into the body-cavity and 



