AMPHIBIOUS VERTEBRATES. 



203 



with which they cling to trees and any surface. Their 

 habits are very singular. In tropical Africa, a species 

 (Polypedates) deposit their eggs on leaves by the side of 

 streams into which they are washed by the rain. In the 

 Island of Guadeloupe there are no marshes, and the young 

 tree-toads appear directly in the adult shape : this is called 

 a sttppressed metamorphosis. A tree-toad in Martinique 

 carries its young tadpoles clinging to its back, presenting 

 a strange sight. In the Andes, a toad {Nototrema) has a 

 sac on its back in which the young are carried. The most 

 remarkable tree-toad is a flier (Rhacophorus, Fig. 244) from 

 New Guinea. Its toes and fingers are completely webbed 

 so that they form parachutes, the little creature springing 

 from limb to limb like a flying-squirrel. They are four 

 inches in length, the web of the hind-feet expanding four 

 square inches. Nearly all tree-toads are green or brown 

 in color, adapted to the leaves or limbs of trees, thus escap- 

 ing their enemies. Hyla micans exudes a luminous secre- 

 tion that may serve to frighten its enemies, while a French 

 species exudes when attacked a strong, pungent odor. 



VALUE. The 



tree-toads protect 

 the trees from 

 noxious insects. 

 Hyla arborea is 

 used as a barome- 

 ter, placed in a 

 bottle, with a small 

 ladder upon which 

 they ascend in 

 pleasant weather, 

 remaining at the 

 bottom if it prom- 

 ises to be inclem- 

 ent. In the Su- 

 rinam toad (Fig. 

 245), allied to the 

 family, the male 



FIG. 245. Surinam toad, showing young escaping 

 from the cells in the mother's back. 



