REPTILES. 195 



reptiles. Why this exception is made in this order we 

 know not. 



321. In Fig. 158 (page 194) is represented the common 

 Crocodile. Its muzzle is more elongated than that of the 

 Alligators. That of the Crocodile of the Ganges, called 

 the Gavial, is more prominent still, and it is terminated 

 by a cartilaginous or gristly protuberance, in which are 

 the openings of the nostrils. This animal is frequently 

 twenty-five feet long, and is very formidable from its 

 strength and ferocity. It is of great service in devour- 

 ing the dead bodies of men and animals which are com- 

 mitted to the sacred river, and which would otherwise 

 taint the air in their decay. 



322. The Alligators or Caymans are less aquatic than 

 the Crocodiles. They frequent swamps and marshes 

 more than rivers. They are very dexterous in catching 

 fish. They sometimes drive a shoal of them into a creek, 

 and then with open mouth plunge among them. They 

 also catch pigs, dogs, and other animals that venture too 

 near the water. 



Questions. What are the two great classes of cold-blooded Verte- 

 brates ? How do they differ in regard to heat from the warm-blood- 

 ed ? What expedients are adopted in the latter to prevent the heat 

 from escaping ? What is said of the name, Reptile ? What is said 

 of the skeleton of reptiles ? What of their power of motion ? De- 

 scribe the circulation of the warm-blooded Vertebrates. Describe that 

 of Reptiles. What relation has the peculiarity of their circulation to 

 their motion ? What is said of their tenacity of life ? What be- 

 comes of them in winter in temperate climates? What is said of the 

 nervous system of the senses in reptiles? What is their food ? What 

 is said of the manner in which serpents eat ? In what are reptiles 

 like birds ? What are the orders of reptiles ? Describe the covering 

 of Tortoises ? What is said of life in them ? What are their fami- 

 lies ? What is said of the Land Tortoises ? Of the Marsh Tortoises ? 

 Of the River Tortoises ? Of the Marine Tortoises ? Of the Green 

 Turtle ? What is said of the two groups of Crocodiles ? What is the 

 peculiarity in the circulation in this order ? What is said of the com- 

 mon Crocodile ? What of the Alligator ? 



