THE VERTEBRATES 203 



frequently heard in the autumn, too, but "its voice is less 

 vivacious than in the spring, and its lonely pipe in dry wood- 

 lands is always associated with goldenrods and asters and 

 falling leaves." The tree-frogs of North America lay their 

 eggs in the water on some fixed object like an aquatic plant, 

 in smaller packets than those of the true frogs, and not in 

 strings as do the toads. 



"The Frog Book" by Mary Dickerson is a well-illustrated and com- 

 plete account of the frogs and toads of this country. 



The salamanders (figs. 100 and loi) are batrachians, with 

 the body not short and tailless as in the frogs and toads. 



Fig. 100. The Western brown eft, or salamander, Diemyctylus torosus. 

 (From life.) 



but elongate and slender and tailed. Their life-history 

 is like that of the frogs, although some salamanders which 

 live on land (they are to be found under logs and stones 

 in the woods) produce their young alive. The little green 

 triton or eft of the Eastern States, or its larger brown-backed 

 congener (fig. 100) of the Pacific coast, is common in water, 

 while another eft, the little red-backed, salamander, is com- 

 mon in the woods under logs and stones. 



The reptiles. — ^The class of reptiles includes the liz- 

 ards, snakes, tortoises, turtles, crocodiles, and alligators. 

 They are cold-blooded and breathe for their whole life 

 exclusively by means of lungs, the forms which live in water 

 coming to the surface to breathe. They are covered with 

 horny scales or plates which with the entire absence of 



