14 CLASSIFICATION. 



9. Each one of these divisions and sub-divisions of the animal 

 kingdom has a particular name. For example; one of the 

 branches is called the branch of the vertebrata, (or vertebrated 

 animals,) another the branch of the molluscous animals, or 

 mollusca, &c.; the first of these branches is divided into many 

 classes, one of which is known as the class of birds, another as 

 the class of reptiles, &j"c. 



10. To enable the naturalist to know whether the animal 

 which he studies, belongs to this or that branch or family, &c., 

 it is necessary that each of the divisions and sub-divisions, under 

 consideration, should be established by characters, easily recog- 

 nised, and derived from the conformation of the animals themselves. 



1 1. Therefore, each branch, each class, each family &c., should 

 comprise all animals which possess certain peculiarities of organi- 

 zation which are not found in animals belonging to other branches 

 or other divisions. The BRANCH of VERTEBRATED ANIMALS, for 

 example, comprises every animal whose body is sustained by an 

 internal skeleton; the CLASS OF FISHES comprises all vertebrated 

 animals which, in place of lungs, have branchiae. To know 

 whether an animal belongs to the branch of vertebrata, it is suffi- 

 cient to examine whether it has an internal skeleton, and this 

 character once ascertained, it cannot possibly be confounded 

 with any animal belonging to the other branches. To know 

 whether a vertebrated animal belongs to the class of fishes or to 

 another class, we must ascertain whether it be provided with 

 branchiae or lungs. 



12. [To illustrate the utility of classification, a few examples 

 will suffice: if one would, without resorting to some such means, 

 ascertain the name of an animal that he had killed in the chase, 

 it would be necessary to compare it with a detailed description of 

 all other animals ; for if, even when at the very beginning of 

 this inquiry, we should meet with a description which seemed 

 to correspond to the object in question, we could not be sure, 

 until we had run over all the other descriptions, that we should 

 not find one still more exactly applicable to this being ; the labor 

 would be consequently almost interminable. But if we employ 



9. How are the divisions and sub-divisions of ihe animal kingdom designa- 

 ted ? What are the examples ? 



10. By what means is a naturalist enabled to know whether an animal 

 belongs to this or that branch, or family ? 



11. What is the distinguishing character of those animals which belong 

 to the branch of vertebrated animals? What is the distinguishing character- 

 istic of fishes ? How do you recognise an animal that belongs to the branch 

 of the vertebrata ? How do we know whether a vertebrated animal belongs 

 to the class of fishes ? 



12. Give an illustration of the utility of classification ? 



