PHYLUM CHORDATA 



309 



tadpoles are ready to be hatched. In Rhinoderma darwini^ 

 a little South American Frog, they are transferred by the male 

 to his immense vocal sacs, which extend over the whole ventral 

 surface, and there hatched. In another Anuran, Nototrema 

 (Fig. 956), there is a pouch on the back of the female in which 



Ov.~~ 



Fit;. ( .C).">. Diagrams of urhiogeuital organs of male (A) and female (B) Urodele. a, collecting 

 tubes; GN, sexual portion of kidney; Ho, testis; Iff. (Ur.) Wolffian duct (ureter); mg, mg'. 

 vestigial Miillerian duct of male; ing. (Od), oviduct; N, non-sexual portion of kidney ;_ 

 Oc. ovary; Ve, vasa efferentia; t, longitudinal canal. (From Wiedersheim's Comparative 

 Anatomy, after Spengel.) . ^ 



the eggs are stored, .the young being hatched in some species 

 as tadpoles, in others in the adult or Frog-form. In the Surinam 

 Toad (Pipa americana, Fig. 957) the skin on the back of the 

 female becomes soft and spongy during the breeding season : the 

 eggs are placed on it by the male, and each sinks into a little pouch 

 VOL. II U 



