DIVISION OF THE ANIMAL KINGDOM INTO GROUPS. 19 



If, in order to become acquainted with the Animal 

 Kingdom, it were necessary to study all the kinds of ani- 

 mals, one by one, a life-time would be much too short to 

 gain a knowledge of the subject. But it is an interesting 

 and encouraging fact, that the Animal Kingdom has been 

 so constructed by the Creator, that, by the thorough study 

 of a few animals, we may learn the most important facts 

 and principles concerning all animals. 



And ii is absolutely essential for the student of Zoology 

 to become thoroughly acquainted with a few of the typical 

 forms of animals, by studying the animals themselves, if 

 lie would have any clear and definite conception of the 

 Animal Kingdom, and of Zoology as a science. 



Ever since men began to study animals, they have en- 

 deavored to classify them. That is, they have endeavored 

 to observe how the different kinds are related to one 

 another, and to express that relation in written language. 

 And it may be stated here, that the investigation of the 

 true relations or affinities of animals w T ith one another, is 

 one of the highest departments of study connected with 

 the science of Zoology. And, as one of the results of this 

 sort of study, naturalists have learned that the Animal 

 Kingdom may be divided into more or less distinctly-marked 



roups. These groups have been named 



BRANCHES, 



CLASSES, 



ORDERS, 



FAMILIES, 



GENERA, 



and SPECIES. 



That is, the Animal Kingdom is divided into Branches, 

 each branch into Classes, each class into Orders, each order 



