FUNDAMENTAL RELATIONS OF ANIMALS 37 



habitat of animals, it is chiefly because they have taken this habitat 

 as the foundation of their primary divisions; but reduced to its 

 proper limits, the study of the connection between the structure 

 and the natural home of animals cannot fail to lead to interesting 

 results, among which the growing conviction that these relations are 

 not produced by physical agents, but determined in the plan ordained 

 from the beginning, will not be the least important. 



The unequal limitation of groups of a different value upon the 

 surface of the earth produces the most diversified combinations pos- 

 sible, when we consider the mode of association of different families 

 of animals and plants in different parts of the world. These com- 

 binations are so regulated that every natural province has a character 

 of its own, as far as its animals and plants are concerned, and such 

 natural associations of organized beings extending over a wider or 

 narrower area are called FauncE when the animals alone are con- 

 sidered, and Flora when the plants alone are regarded. Their natural 

 limits are far from being yet ascertained satisfactorily everywhere. 

 As the works of Schouw and Schmarda may suffice to give an ap- 

 proximate idea of their extent,^^ I would refer to them for further 

 details and allude here only to the unequal extent of these different 

 faunas and to the necessity of limiting them in different ways, ac- 

 cording to the point of view under which they are considered, or 

 rather show that as different groups have a wider or more limited 

 range, in investigating their associations or the faunas, we must dis- 

 tinguish between zoological realms, zoological provinces, zoological 

 counties, zoological fields, as it were; that is, between zoological areas 

 of unequal value over the widest of which range the most extensive 

 types, while in their smaller and smaller divisions we find more and 

 more limited types, sometimes overlapping one another, sometimes 

 placed side by side, sometimes concentric to one another, but always 

 and everywhere impressing a special character upon some part of a 

 wider area, which is thus made to differ from that of any other part 

 within its natural limits. 



These various combinations of smaller or wider areas, equally well 

 defined in different types, has given rise to the conflicting views pre- 



^ I would also refer to a sketch I have published of the Faunae ("Sketch of the 

 Natural Provinces of the Animal World and Their Relation to the Different Types of 

 Man," in J. C. Nott and George R. Gliddon, Types of Mankind, Philadelphia, 1854, 

 accompanied with a map and illustrations, pp. Ivii-lxxviii). 



