ORGANIC GEOLOGICAL DYNAMICS. 621 



briefly refer to some points, availing myself of hi 

 labours and his ideas. 



Sect. 2. Geography of Plants and Animals. 



WITH regard both to plants and animals, it ap- 

 pears 1 , that besides such differences in the products 

 of different regions as we may naturally suppose to 

 be occasioned by climate and other external causes; 

 an examination of the whole organic population of 

 the globe leads us to consider the earth as divided 

 into provinces, each province being occupied by its 

 own group of species, and these groups not being 

 mixed or interfused among each other to any great 

 extent. And thus, as the earth is occupied by 

 various nations of men, each appearing, at first 

 sight, to be of a different stock, so each other tribe 

 of living things is scattered over the ground in a 

 similar manner, and distributed into its separate 

 nations in distant countries. The places where spe- 

 cies are thus peculiarly found, are, in the case of 

 plants, called their stations. Yet each species in its 

 own region loves and selects some peculiar condi- 

 tions of shade or exposure, soil or moisture : its 

 place defined by the general description of such 

 conditions, is called its habitation. 



Not only each species thus placed in its own 

 province, has its position further fixed by its own 

 habits, but more general groups and assemblages 



1 Lyell, Principles, B. iii. c. v. 



