ORIGIN OF ORGANIC FORMS 307 



the very essentials of the conception of the origin of 

 species by variation, we shall see in what relation this 

 argument stands to Darwin's theory. At present we 

 need only note the fact that this theory has employed 

 in its own defence the very weapon of its adversaries ; 

 it entirely accounts for the absence of transitional forms. 

 Indeed their very existence would have served as a 

 strong argument against it. This is one of its essential 

 points, the reason for its ascendency over other 

 attempts of the same kind. 



So far we have brought forward arguments and done 

 our best to refute those who have contradicted the fact 

 that the organic world has a history. We have tried to 

 prove by means of concordant evidence from all depart- 

 ments of biology that the affinity of organisms, admitted 

 by all naturalists without exception, can only be explained 

 by their close relationship. Hence organisms have a 

 genealogy, a history. ' Turning to the second half of 

 our problem, we must now prove that this historical 

 process necessarily leads to the perfection of organisms, 

 implying by perfection the adaptation of the organ to 

 its function, of the organism to its environment. Observ- 

 ing that the organic world presents beings in all stages 

 from the simplest to the more perfect, and realising that 

 this perfection corresponds with the chronological 

 order in the appearance of these beings upon the earth, 

 many naturalists have even seen in this fact a proof 

 that the organic world is endowed with a tendency to- 

 wards perfection, and that this property needs no further 

 explanation. Others again have tried to give a more 

 rational explanation of the fact, though with ill success 

 for the most part. Darwin was the first to point out 

 the immediate causes, very general laws of Nature, 

 which .result in the progressive development, the 

 evolution, of the organic world. He used for this purpose 



