FROGS, TOADS, SALAMANDERS, SNAKES, ETC. 155 



The colors of the frog are admirably adapted to conceal it. 

 The species that sit most of the time along the edges of pools 

 and swamps are so colored and mottled as to resemble closely 

 the water plants among which they live and try to conceal 

 themselves. Those that are more terrestrial are similarly 

 protectively colored. This is especially well shown in the 

 small tree frogs, which are able to change their color within 

 limits, according to the surface upon which they sit. When 

 we think of the snakes, turtles, cranes, herons, bitterns, ducks, 

 crows, hawks, owls, and different mammals that are always 

 on the lookout for frogs, we can see the wisdom of such pro- 

 tective coloring. 



Another peculiarity, shared with other amphibians and 

 reptiles and many other animals, is the habit of sleeping 

 through the winter. Only the frog sleeps in the mud at the 

 bottom of ponds and swamps, imder the ice, where he stays 

 till spring releases him. At this time the skin is the organ of 

 respiration. 



It may be asked of what use are frogs. They play their 

 part in nature, and on the whole a useful one. They destroy 

 a vast number of insects, and they themselves serve as food 

 for other animals. They are good for bait, and frogs' legs 

 are used as food in large quantities by man. 



There are a number of species of frogs. The following 

 are some of the most commonly seen. 



The Bullfrog is the largest, and may be recognized by its 

 deep base voice. It is of greenish color above, mottled with 

 irregular blotches of brown or black, and underneath it is 

 white. The web extends to the tip of the fourth toe. It is 

 found in swampy places. 



The Leopard Frog is the most common. It has a greenish 



