THE CLASSIFICATION OF ANIMALS 53 



Plainly related to the Canidce, for example, are the Felidce, or 

 cats and cat-like animals, the Ursidce, or bears, Mustelidce or 

 weasels, and some other families all of whose members are 

 carnivorous in habit and have teeth, feet, and other parts 

 specially modified in connection with this habit. All of these 

 families then are grouped together to form the order Carnivora. 

 All the families of hoofed animals, as the Equidce or horses, the 

 Bovidce or cattle, the Cervidce or various deer kinds, and other 

 similar families, compose the order Ungulata. But all the 

 animals of both Carnivora and Ungulata as well as of a number 

 of other orders agree in possessing certain important common 

 characteristics of structure and physiology, which undoubtedly 

 indicate a certain relationship. And so they are grouped to- 

 gether to form a class. The particular class comprising the 

 orders just spoken of is named the Mammalia, from the posses- 

 sion by all of its members of milk glands for producing milk 

 for their young. 



Finally there is a plain relationship among the class Mam- 

 malia or mammals, and the class Aves, or birds, the class 

 Reptilia, or reptiles, the class Amphibia, or batrachians and the 

 class Pisces or fishes. They are all back-boned animals, while 

 other animals are not. They may be grouped together into 

 a single large group called a branch. The name of this branch 

 is the Chordata. There are eleven other branches in the animal 

 kingdom, all of which are named and divided into their classes 

 in the table on pages 55 to 57. 



The branches are the largest groups used in the classi- 

 fication of animals, so that if we should now tabulate the 

 scientific classification of our dog we should find it to belong 

 to the 



kingdom Animalia 

 branch Chordata 

 class Mammalia 



order Carnivora 

 family Canidae 

 genus Canis 



species familiaris. 



Its scientific name is, however, simply Canis familiaris, which 

 indicates, to a zoologist, the whole classification of the dog. 



