CLASSIFICATION 105 



Primates (monkeys, apes, and man), and a number of other 

 orders in one class, the class Mammalia. The members of this 

 class are called mammals, and all have certain characteristics 

 in common; among these are a covering of hair, and the 

 presence of milk glands from which the helpless young obtain 

 food. 



The animals in the class Mammalia and in the classes contain- 

 ing the birds, reptiles, fish, and eels resemble one another in the 

 possession of a backbone, made up of a series of bones called 

 vertebra, and are hence grouped together in the phylum Verte- 

 brata. The vertebrates are the only animals that possess a back- 

 bone. 



The rest of the animals in the animal kingdom are arranged in 

 a similar way and we may recognize ten phyla in all as indicated 

 on page 6. 



The system described above may be applied to man as 

 follows : 



George Washington was an individual; he belonged, with 

 other men, to the species sapiens of the genus Homo. This 

 genus, together with another of somewhat questionable relation- 

 ships, the extinct Pithecanthropus , constitutes the family Homin- 

 idce. The Hominida are included with ten other families of 

 monkey-like animals in the order Primates. Fifteen related 

 orders, of which the Primates form one, are placed in the class 

 Mammalia. The class Mammalia with four other classes make 

 up the phylum Vertebrata. The scientific name of man is writ- 

 ten Homo sapiens Linnasus. 



Reasons for Existence of Classification. — There are several 

 important reasons why a classification of animals exists. In the 

 first place it seems natural for us to group similar things to- 

 gether, and this has been done ever since the time of the Greek 

 naturalist Aristotle (384-322 B.C.) who gave us the first valuable 

 writings on animals. For example, we are all the time uncon- 

 sciously classifying human beings, grouping them into nations, 

 such .as the English, French, German, etc., or into races, as the 



