CLASSIFICATION, 15 



the method of classification, we shall arrive almost at once, and 

 without difficulty, at the end of our search. I will suppose that 

 the animal in question is an eagle ; I find at first that it has a 

 skeleton, and hence I know that it belongs to the branch of ver- 

 tebrala^ and it is not necessary to compare it with animals of the 

 other branches ; I next look for the characters which distinguish 

 the different classes of vertebrata from each other, and when it is 

 determined in this way, that it is an animal of the class of birds, I 

 exclude from the comparison which remains yet to be made, all 

 the mammalia, all the reptiles, and all the fishes; I next inquire 

 whether it presents the characters proper to this or that order of 

 the class of birds, this or that family ; and when I have ascer- 

 tained the genus to which it belongs I have only to compare it 

 with a very small number of animals from which it differs only 

 in some few, not very important particulars.] 



1 3. [The use of classification permits the abbreviation, to a con- 

 siderable extent, of the description otherwise necessary to make 

 another recognise any particular animal ; for if we say that an 

 animal is a vertebrata of the class of reptiles, of the order of 

 sauria, of the family of crocodiles, it requiresj in order to dis- 

 tinguish it, only to point out the characters by which it differs 

 from a very small number of other animals, which possess, in 

 common with it, characters peculiar to the order and family of 

 which it also forms a part. There exists here the same difference 

 as would be found in seeking, by his description and number, a 

 soldier in an army in which all the ranks were mingled, or in a 

 well-regulated army where each division, each brigade, each 

 regiment, each battalion, each company, would be found in the 

 place belonging to them, and carrying with them their distinctive 

 signs.] 



14. [By the assistance of zoological classification we are enabled 

 to assign to an animal the name which belongs to it, in the same 

 manner as we are enabled to find a person we seek by knowing 

 the direction of his residence ; in the latter case we first inquire 

 his country, then the state, the county, the town, the street, the 

 house, and finally the room in which he dwells ; and in the first 

 case we ask to what grand division of the animal kingdom does 

 the species under consideration belong, then to what class, what 

 order, what family, and to what genus it must be assigned ; these 

 questions being solved the work is almost finished.] 



15. As we have seen, it is by the differences existing between 



13. What is the striking use of classification? Illustrate its use? 



14. What does zoological classification enable us to do ? 



15. By what means are we able to classify animals ? On what principle 



