1 6 ESSAY ON CLASSIFICATION. 



the contrary, that these organisms may have appeared 

 in the beginning over a wide area, is to grant, at the 

 same time, that the physical influences under which they 

 existed at first were not so specific as to justify the as- 

 sumption that these could be the cause of their appear- 

 ance. In whatever connection, then, the first appearance 

 of organized beings upon earth is viewed, whether it is 

 assumed that they originated within the most limited 

 areas, or over the widest range of their present natural 

 geographical distribution, animals and plants being every- 

 where diversified to the most extraordinary extent, it is 

 plain that the physical influences under which they sub- 

 sist cannot logically be considered as the cause of that 

 diversity. In this, as in every other respect, when con- 

 sidering the relations of animals and plants to the condi- 

 tions under which they live or to one another, we are 

 inevitably led to look beyond the material facts of the 

 case for an explanation of their existence. Those who 

 have been led to take another view of this subject have 

 mistaken the action and reaction which exist everywhere 

 between organized beings, and the physical influences 

 under which they live, 1 for a casual or genetic connec- 

 tion, and carried their mistake so far as to assert that 

 these manifold influences could really extend to the pro- 

 duction of these beings; not considering how inadequate 

 such a cause would be, and that even the action of physi- 

 cal agents upon organized beings presupposes the very 

 existence of those beings. 2 The simple fact that there 



fauna and the first flora which have while, in a wider area, physical agents 

 existed upon earth, special relations, are too uniform in their mode of ac- 

 special contrivances must, therefore, tion to have laid the foundation for 

 have been provided. Now, what would so many specific differences as ex- 

 be appropriate for the one would not isted between the first inhabitants 

 suit the other, so that, excluding one of our globe, 

 another in this way, they cannot J See below, Sect. 16. 

 have originated upon the same point; 2 A Critical examination of this 



