STRUCTURE OF REPTILES. US 



LESSON XX. 



REPTILES STRUCTURE OF REPTILES CLOTHING 



OF REPTILES POISONOUS ANIMALS. 



REPTILES form, the next class of living objects. 

 The word reptile signifies in general any thing 

 which creeps, but it is used in a more strict sense 

 by naturalists. Frogs, lizards, crocodiles, alliga- 

 tors, tortoises, turtles, and serpents, are amongst 

 the reptiles. 



Reptiles differ very widely from both the mam- 

 malia and from birds in structure, habits, and 

 appearance. The latter have red, or warm blood, 

 and are of the same heat as ourselves, and are 

 hence called warm-blooded animals: but in rep- 

 tiles, the blood is of a paler colour, and they 

 generally feel cold to the touch, and have in con- 

 sequence been called cold-blooded animals. They 

 breathe, however, by means of lungs, which are 

 transparent, and of very fine texture, and they are 



