THE BULLFROG 



105 



in the shape of gills to be detected beside the neck, nor 

 yet any tail. There were, however, certain folds on each 

 side of the body which may turn out to be peculiar 

 temporary breathing organs, like the respiratory tail of 

 the Hylodes before mentioned. 



Another American tree frog, named Xototrema, has a 

 Fig. 27. 



THE PIPA 



curious pouch which extends in the female over the whole 

 of the back and opens posteriorly. Into this opening 

 the eggs are introduced as soon as laid, and the young un- 

 dergo their process of development in this large cutaneous 

 maternal sac. Of course they have no opportunity of 

 living the life of tadpoles. Neither have the young of the 

 well-known kind next to be described. 



This latter kind is the great South American toad 

 called the Pipa, whose mode of reproduction was at first 



