206 ZOOLOGY. 



and given a powerful interest to that part of botany and 

 zoology which heretofore was the most arid. 



The distinguished men to whom we owe this innovation 

 began with plants, which before their time were arranged 

 arbitrarily by the number of their stamens and pistils, or 

 after some other character chosen without regard to their 

 analogies. Towards the middle of the last age, a French 

 botanist, Bernard de Jussieu, conceived the happy idea of 

 distributing them in groups according to the whole of their 

 organization ; and his nephew, Antoine -Laurent de Jussieu, 

 applied this idea to the entire of the vegetable kingdom, and 

 assuming as a basis of his classification the consideration of 

 the dominating characters (see 357), created the natural 

 method at present adopted by all naturalists. 



370. Mode of Division of the Animal Kingdom. 

 The animal kingdom is composed only of individuals ; but 

 among these there is a certain number which have an 

 extreme resemblance to each other, and which are reproduced 

 with the same essential characters ; these reunions of indi- 

 viduals formed after the same type, constitute what naturalists 

 call species. Thus man, dogs, horses, form for the zoologist 

 so many distinct species. 



Sometimes the species differs considerably from all others ; 

 but in general there exists a number more or less considerable 

 which strongly resemble each other, and which are only 

 distinguished by differences of little importance ; such as the 

 horse and the ass, the dog and the wolf. For natural 

 classifications, these closely allied species are reunited into 

 groups called genera, and to their specific name a generic 

 name is also added, common to them all ; thus we say the 

 grey, the spotted, the ocellated lizard, &c., to designate diffe- 

 rent species of the genus lizard ; and brown bear, white bear, 

 &c., for the different animals of the genus bear. Genera 

 which resemble each other are grouped together by the name 

 of tribe, or natural family. 



If we afterwards consider the structure of animals in a 

 more general way, we cannot fail to recognise in several 

 families the same dominating characters, thus giving to them 

 in spite of their differences, a certain common character. In 

 this way the naturalist forms divisions of a more elevated 

 rank, which he calls orders, and reunites in turn these 

 orders into groups still more numerous, called classes. 

 But the classes themselves admit of being divided by the 



