206 VERTEBRATA 



The commonest of our frogs is the leopard frog (Rana 

 pipiens) distinguished by the two rows of irregular black 



blotches on the back and 

 the bars on the upper surface 

 of the legs. 



The tree frogs or tree toads 

 are so named from their 

 habit of climbing trees, to 

 which they adhere by means 

 of small expansions at the 

 extremities of the toes. 

 They have the power to 

 change their color to har- 

 monize with their surround- 

 ings. The common tree frog 

 (Hyla versicolor) is the one 

 FIG. 239. The spring peeper, photo- giving the high trilling note 



graph natural size. , . ,, 



prophetic of the approach- 

 ing storm; The Spring peeper (Hyla pickeringii) an- 

 nounces the coming spring by its clear shrill whistle 

 " Uh-e-e-t, wh-e-e-t, wh-e-e-t," 

 uttered so continuously at night- 

 fall that every meadow and swamp 

 seems to be the home of thou- 

 sands. They may be caught by 

 wading among them with a lan- 

 tern and then remaining quiet 

 about ten minutes until one moves FIG. 240. -The toad one third 

 sufficiently near to be grasped. natural 8ize * 



Toads differ from frogs in having no teeth in either jaw, 

 and usually the skin presents a warty appearance. The 



