PIG. 47. 1, FEOG (Rana temporaria). 2, TOAD (Bufo vulgaris). 3, TADPOLE: 



EEPTILES. 



These constitute the second class of the Vertebrate 

 animals. They are divided into four orders. 



1. AMPHIBIA (double-lived). 



By some naturalists a separate class is made out of the Am- 

 phibia, including the Frog kind, Toads, and Newts (fig. 

 47), which they call "Batrachia," and which takes a place 

 between Eeptiles and Fishes, as the young of this class 

 have a totally different form from the adult animal, and 

 much resemble a fish, breathing by gills and having no 

 legs, but as they become mature the gills are replaced 

 by lungs, and the legs make their appearance. 



The Amphibia have soft skins, which appear to serve 

 as lungs or gills when they are under the water, extract- 

 ing the air from it, and enabling them to remain a long 

 time there without coming up to breathe; they are partly 

 aquatic, and feed upon insects and other small creatures, 

 which they capture by darting out the tongue, which is 

 covered with a glutinous secretion, and drawing it in 

 again instantly with the insect adhering to it, which 



