262 



A YEAR IN SCIENCE 



lose their gills and breathe by means of lungs as do the 

 higher animals. The body is covered with a soft, slimy 

 skin. Amphibians are also cold blooded animals. Frogs, 

 toads, and salamanders belong to this group. Some of 



Fig. 119. Stages in the^development of the frog. 



these, especially the salamanders, greatly resemble 

 lizards. From these animals they are most easily dis- 

 tinguished by the absence of scales. 



