AMPHIBIANS 



441 



the young ultimately escape as minute toads (fig. 965). No gills 

 appear to be present in the tadpole stage. When not employed 

 as a nursery the pouch is of modest dimensions, only stretching 

 about half-way down the chest, but as the eggs develop it 

 gradually extends along the whole under surface and round the 

 sides. 



In some tailless forms the eggs are carried about by the 

 female, the arrangements made for their safety varying according 



Fig. 965. Male of a Chilian Toad (Rhinoderma Danvini). i, Skin removed to show brood-pouch; 



2, brood-pouch opened. 



to the species. A well-known case is that of the Surinam Toad 

 (Pipa Americana, fig. 966), in which the sticky eggs are spread 

 by the male over the back of his mate. Where each of them is 

 affixed a little pouch is formed in the skin, exactly how is un- 

 known, and afterwards a lid comes into existence, possibly by 

 hardening of the egg-investment. Within these sheltered re- 

 cesses the whole of the development takes place, and when the 

 young begin their free existence they have already attained the 

 form of the adult. 



In one of the Cingalese tree-frogs (Rhacophorus reticulatus) 

 the female places her score or so of eggs on the under side of her 

 body, where they sink into the skin, little pits being formed some- 



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