30 



THE COMMON FROG. 



[chap. 



4 



of the female's back at the laying season thickens 

 greatly and becomes of quite a soft and loose tex- 

 ture. The male, as soon as the eggs are laid, takes 

 them and imbeds them in this thick, soft skin, which 

 closes over them. Each <tgg then undergoes its 

 process of development so enclosed, and the tadpole 

 stage is, in this animal, passed within the ^gg, so 



Fig. 1 1. --The Sarinam Toad {Pipa aiiiertcana). 



that the young toad.s emerge from the dorsal cells 

 of the mother completely developed miniatures of 

 the adult. As many as 120 of these dorsal cells 

 have been counted on the back of a single indi- 

 vidual. 



The only instance of a similar cutaneous modi- 

 fication is that pointed out by Dr. Gunther^ in the 



1 See Catalogue of the Fishes in the British Museum, vol. v. p. 268. 



