44 Darwin, and after Darwin. 



display a progressive advance of organization from 

 below upwards. 



Now we have seen that although this tree-like 

 arrangement of natural groups was as suggestive as 

 anything could well be of all the forms of life being 

 bound together by the ties of genetic relationship, 

 such was not the inference which was drawn from it. 

 Dominated by the theory of special creation, natu- 

 ralists either regarded the resemblance of type subor- 

 dinate to type as expressive of divine ideals mani- 

 fested in such creation, or else contented themselves 

 with investigating the facts without venturing to 

 speculate upon their philosophical import. But even 

 those naturalists who abstained from committing 

 themselves to any theory of archetypal plans, did 

 not doubt that facts so innumerable and so uni- 

 versal must have been due to some one <x>-ordi- 

 nating principle that, even though they were not 

 able to suggest what it was, there must have been 

 some hidden bond of connexion running through the 

 whole of organic nature. Now, as we have seen, it is 

 manifest to evolutionists that this hidden bond can be 

 nothing else than heredity ; and, therefore, that these 

 earlier naturalists, although they did not know what 

 they were doing, were really tracing the lines of 

 genetic descent as revealed by degrees of structural 

 resemblance, that the arboresent grouping of organic 

 forms which their labours led them to begin, and in 

 large measure to execute, was in fact a family tree of 

 life. 



Here, then, is the substance of the argument from 

 classification. The mere fact that all organic nature 

 thus incontestably lends itself to a natural arrange- 



