TREE-CLIMBING FROGS 



137 



in Nature's ascending scale, is of great use, and in all prob- 

 ability it is the principal factor in the arboreal life of these 

 animals. 



In South America there are several species of tree frogs 

 whose females carry their eggs, during incubation, in pouches 

 or cells upon their backs. It is believed that the eggs are 



NORTHERN TREE FROG. 



Natural size. Photographed at the instant of croaking, 

 and copyright, 1903, by W. Lyman Underwood. 



placed in position and embedded there by the male frogs. 

 Other species attach their eggs to leaves that are afterward 

 rolled together at the edges. Others deposit their eggs at 

 the bases of large leaves where water collects, and some are 

 credited with placing them where they will fall into pools, to 

 be hatched there. A Brazilian species called the "Smith" 1 

 constructs, at the edge of a pool, a really wonderful circular 

 wall or fortress, of mud, in which its eggs are deposited. 



1 Hy'lafa'ber. 



