118 ANIMAL BIOLOGY 



history of the toad is much the same as in the case of the frog. As 

 soon as metamorphosis is complete, the little toads leave the water 

 and often are found considerable distances away from water. 



Less like the frog, at least in its adult stage, are the salamanders 

 and newts (Fig. 88). These are found in damp places or in 



FIG. 88. The newt. 



water and are often called "lizards," by those who do not know 

 that a lizard has scales, claws on its feet, and breathes throughout 

 its life by means of lungs. Some of the relatives of the frog, even 

 after they have developed lungs, retain gills throughout their 

 life (Fig. 89). 



FIG. 89. A mature amphibian (Necturus) with external gills. 



Because of the ability of the animals described in this chapter to 

 live both on the land and in the water, they are called the amphibia, 

 from Greek amphi = both + bios = life. 



88. Economic importance of the amphibia. None of 

 the amphibia, so far as is known, are harmful to man. On 

 the contrary, all of them are more or less useful because of the 

 insects that they devour. This is especially true of the garden 

 toad. It has been estimated by one author that a toad in 

 a garden is worth nearly twenty dollars a year on account 

 of the cutworms and other injurious insects that it destroys. 

 " In France the gardeners even buy toads to aid them in 



