ARISTOTELIAN PERIOD. 9 



introduction of the species upon the earth, the duration 

 of its existence as a species, its geographical range in 

 past time, and various other similar points. The study 

 of these questions constitutes another department of 

 natural history, which is known under the name of 

 PALAEONTOLOGY. 



In the sixth place, it is necessary to have some clear 

 ideas as to the relations of each species of animals to 

 other species, and as to the place which the species 

 should occupy in the long series of forms of which the 

 entire animal kingdom is made up. The study of this 

 constitutes what is known as the science of CLASSIFICATION 

 or TAXONOMY ; and it is, perhaps, the branch of natural 

 history which most nearly fulfils the popular notion of 

 what natural history really is. A ' naturalist ' is popularly 

 supposed to be a man who can take any animal and 

 give a name to it, and can place it in some particular 

 drawer or pigeon-hole in the great cabinet of nature. 

 Most of the naturalists of the seventeenth and of the 

 earlier half of the eighteenth centuries concerned them- 

 selves principally with questions touching classification; 

 not a few of them, in fact, being little more than 

 'collectors.' While older workers, not unnaturally, were 

 led to give this branch of the science a position of 

 unmerited prominence, there has of late years been 

 shown a tendency unduly to decry the systematic or 

 taxonomic study of natural history, as being a matter 

 of comparatively small moment. In reality, however, it 

 is not possible to study natural history scientifically, 

 unless we start with the foundation of a systematic 

 classification of some kind. Moreover, if we consider 



