CLASSIFICATION AND DISTRIBUTION 373 



them, and a number of different families; but all agree in the 

 living upon flesh, and all sh^w certain points of likeness in the 

 structure of the feet and the skeleton, which place them in a 

 group by themselves, distinct from animals that live upon 

 vegetable foods. All of these flesh-eating animals are, therefore, 

 grouped together into an order called the Carnivora. 



Classes. In a similar way, different orders can be arranged 

 in still larger groups. For example, although there are many 

 points of difference between the carnivorous cat, the herbivorous 

 buffalo, the gnawing rabbit, the flying bat, and the gigantic 

 marine whale, still they all agree in one fundamental character. 

 In all of these orders the females have mammary glands and 

 nourish their young by means of milk, a characteristic which 

 is totally lacking in fishes, reptiles, and birds. It is evident, 

 therefore, that all of these milk-producing animals may prop- 

 erly be classed together under one head. Such a group we then 

 know as a class; in this particular case we name them the 

 Mammalia. 



Phyla. Extending our observations still farther, we find 

 that all of the animals mentioned, together with fishes, reptiles, 

 amphibia, and birds, resemble each other in having bones, which 

 none of the rest of the animal kingdom possesses. The insects, 

 clams, etc., never have bones, but have other characteristics of 

 their own. It is evident, therefore, that all animals possessing 

 bones may be grouped together as distinct from other types. 

 This produces a group that we know as a phylum or sub- 

 kingdom. In this particular case we name the phylum the 

 Vertebrata. 



Kingdoms. Now if we sweep our glance over the whole 

 organic world, we find that it is divided into two groups, the 

 animals and the plants. These large groups we call the animal 

 kingdom and the vegetable kingdom. 



Thus it is seen that the whole organic world is divided into 

 kingdoms, phyla, classes, orders, families, genera, and species. 

 Occasionally we recognize intermediate groups; for instance, 



