CHAPTER I 



CLASSIFICATION AND ADAPTATION 



THE study of the animals and plants now living on 

 the earth naturally divides itself into two branches, 

 the one being concerned with their structure and 

 classification, the other with their living activities, 

 their habits, life histories, and reproduction. Both 

 branches are usually included under the terms 

 Natural History, or Zoology, or Botany, and a 

 work on any group of animals usually attempts 

 to describe their structure, their classification, and 

 their habits. But these two branches of biological 

 science are obviously distinct in their methods and 

 aims, and each has its own specialists. The pursuit, 

 whose ultimate object is to distinguish the various 

 kinds of organisms and show their true and not 

 merely apparent relations to one another in structure 

 and descent, requires large collections of specimens 

 for comparison and reference : it can be carried on 

 more successfully in the museum than among the 

 animals or plants in their natural surroundings. 

 This study, which may be called Taxonomies, 

 deals, in fact, with organisms as dead specimens, 

 and it emphasises especially the distinguishing 

 characters of the ultimate subdivisions of the vari- 

 ous tribes of animals and plants namely, species 

 and varieties. The investigation, on the other 

 hand, of the different modes of life of animals or 



A 



