FROGS, TOADS, AND SALAMANDERS 235 



the meantime the gills disappear and lungs begin to form. 

 Finally, the legs and lungs become fully developed, and 

 the tail wholly disappears. The frog is then considered 

 an adult. Some frogs pass through these changes in one 

 season, but the green frog usually passes the first winter as 

 a tadpole and completes the changes the following summer. 



Habitat and habits. — The frog is found liear ponds, pools, 

 or streams of water. In a quiet walk along the banks of 

 a stream, they may be seen leaping into the water from their 

 resting places in the grass, where they have been in search 

 of food. They are obliged to remain near the top of the 

 water in order to obtain air and usually float at the surface 

 with the head out of the water. In spring they become 

 very musical and congregate in ponds to lay their eggs. 

 After the eggs are laid they scatter to different places to 

 avoid overcrowding and to insure a food supply. In the 

 winter they dive to the bottoms of ponds and burrow into 

 the mud. Here they pass into a state of stupor, with the 

 eyes closed, and the organs of the body inactive. In this 

 condition they are said to be hibernating. 



The common toad. — The toad differs from the frog by 

 the total absence of teeth, by the rough, warty skin, and 

 by the fact that it lives on land, going to the water only in 

 the spring to lay its eggs. It must be said, however, that 

 toads require damp, moist places in which to live. They 

 are often seen in great numbers after a shower because they 

 delight in a cool, moist atmosphere, and come out from their 

 hiding places to enjoy it. They usually remain hidden 

 during the day and come out at dusk and at night to 

 catch insects in the same manner as the frog, for the tongue 

 of the toad is similarly constructed. The alimentary canal, 

 excretory and circulatory organs are similar to those of the 



