02 



REPTILES I5ATRACHIANS DIAGRAM 5. 



End of tail of Rattlesnake. 



it is from this peculiarity that these 

 snakes derive their name. 



All serpents, like lizards, have a 

 forked tongue which they often dart 

 out, and which is sometimes improperly 

 called their sting ; but it is soft, and it is quite impossible for them 

 to do any harm with it. One ought always to destroy as many 

 vipers as possible in a country, but there is no occasion to destroy 

 the common snakes. Vipers, unlike most snakes, do not lay eggs, 

 but bring forth their young alive. 



BATRACHIANS. 

 [ DIAGRAM 5. ] 



The name of this family is derived from a Greek word mean- 

 ing frog ; and it also includes the salamanders. All these ani- 

 mals much resemble other reptiles, but they differ from them in 

 having no scales, but a naked skin, and especially because they 

 come out of the egg in a different form from that which they will 

 afterwards assume ; they thus undergo what is called a metamor- 

 phosis. A frog, for instance, lays eggs. The eggs are trans- 

 parent as jelly, and we soon see the vitellus (which is not yellow 

 as in the fowl, but brown) transformed 

 into an animal which has no re- 

 semblance to a frog ; it is composed of 

 a large head and a tail, and is called 

 a Tadpole. It has two tufts on each 

 side, which are gills, and it has no 

 lungs. It does not breathe the air of 

 the atmosphere. But there is always 

 a certain quantity of air in water ; and 

 this is what forms small bubbles on 

 Tadpole. the sides of a vessel in which water is 



