VERTEBRATES 



271 



names all explain themselves, except perhaps amphibians, 

 which means animals that can live either in water or on 

 the land. Frogs and toads belong to this class. Turtles 

 and alligators, as well as snakes and lizards, belong to 

 the reptiles. Of course you know birds when you see 

 them, but it may surprise you to know that birds are re- 

 lated to reptiles; that is, the first bird was a sort of winged 

 reptile. 



The last and highest class of the vertebrates are the 

 mammals, to which we ourselves belong. Nearly all the 

 domestic animals are also mammals, and many others 

 that are wild furnish us with food or clothing. The name 

 mammals refers to the mammary glands of the female that 

 furnish milk for the young. The fur-bearing animals are 

 all mammals. Fishes, birds, amphibians, and most reptiles 

 lay eggs, but mammals give birth to their young alive. 



Every boy and girl should try to get clearly and per- 

 manently in mind the way in which mammals are classified 

 into different groups. This will help you greatly in organ- 

 izing your knowledge. There is no more fascinating book 

 than Hornaday's "American Natural History" in which 

 you can read of the habits of all the important American 

 vertebrates. 



The mammals are divided into thirteen orders, four of 

 which it is quite important to remember. First come the 

 Primates, which means "first order." To this belong the 

 apes, the monkeys, and man. Then come the carnivorous 

 (flesh-eating) animals. To this order (Ferce) most of our 

 interesting wild animals belong. This order is composed 

 of five families: cats, dogs, bears, martens, and raccoons. 

 Wild members of the cat family in America are the puma 

 and the lynx, while wolves and foxes belong to the dog 



