362 MOSTLY MAMMALS 



to excite our unbounded wonder and admiration. But in 

 many frogs and toads the course of development is modified 

 in various ways from this typical plan in accordance with 

 the special needs of their existence, thus giving rise to 

 many wholly unexpected phenomena and peculiarities. 



The first peculiarity is displayed by the Japanese frog 

 {Rhacophorus schlegeli), in which the eggs are laid in the 

 muddy banks of paddy-fields or ponds above the water- 

 level. The egg-mass is kneaded into a froth by the legs 

 of the female parent, and its exterior hardens into a kind 

 of crust. Within this " pudding" the tadpoles are hatched ; 

 and eventually the mass breaks up into a fluid, and bursts 

 its crust to flow into the water, carrying with it the tad- 

 poles. If the eggs be removed from the " pudding " and 

 transferred to water, they immediately perish. 



In a West African frog {Chwojnantis guineensis), as well 

 as in a Brazilian species {Phyllomedusa iheringi), the eggs, 

 on the other hand, are deposited in nests formed of leaves 

 glued together by the parent. And in both instances the 

 tadpoles swim about within a frothy substance. In the 

 case of the latter species the nest has an opening below 

 through which the tadpoles are eventually discharged into 

 the water over which it is built ; but those of the first 

 species are believed to be washed off" the leaves by rain, 

 falling into water below. 



The female of the little Paraguay tree-frog {Phyllomedusa 

 hypochondrialis) carries her partner on her back until a 

 suitable leaf in the neighbourhood of water is found, when 

 the two parents bend back its tip in such a manner as 

 to form a funnel, in which the female deposits her spawn. 

 Two nests of this description, each containing about one 

 hundred eggs, may be formed by each pair of frogs. 

 After an interval of six days the tadpoles hatch out and 



