AND CLASSIFICATION. 21 



which he has included all animal structures. 

 And this method, so prolific in his hands, has 

 also a lesson for us all. In this country there 

 is a growing interest in the study of Nature ; 

 but while there exist hundreds of elementary 

 works illustrating the native aijimals of Europe, 

 there are few such books here to satisfy the de- 

 mand for information respecting the animals of 

 our land and water. We are thus forced to 

 turn more and more to our own investigations 

 and less to authority ; and the true method of 

 obtaining independent knowledge is this very 

 method of Cuvier's, comparison. 



Let us make the most common application of 

 it to natural objects. Suppose we see together 

 a Dog, a Cat, a Bear, a Horse, a Cow, and a 

 Deer. The first feature that strikes us as com- 

 mon to any two of them is the horn in the Cow 

 and Deer. But how shall we associate either of 

 the others with these ? We examine the teeth, 

 and find those of the Dog, the Cat, and the Bear 

 sharp and cutting, while those of the Cow, the 

 Deer, and the Horse have flat surfaces, adapted 

 to grinding and chewing, rather than cutting 

 and tearing. We compare these features of 

 their structure with the habits of these animals, 

 and find that the first are carnivorous, that they 

 seize and tear their prey, while the others are 

 herbivorous or grazing animals, living only on 



