AN HISTORICAL SKETCH 



OF THE PROGKESS OF OPINION ON THE OEIGIN OF SPECIES, 



PREVIOUSLY TO THE PUBLICATION OF THE FIRST EDITION 



OF THIS WORK. 



I will here give a brief sketch of the progress of 

 opinion on the Origin of Species. Until recently the 

 great majority of naturalists believed that species were 

 immutable productions, and had been separately created. 

 This view has been ably maintained by many authors. 

 Some few naturalists, on the other hand, have believed 

 that species undergo modification, and that the existing 

 forms of life are the descendants by true generation of 

 pre-existing forms. Passing over allusions to the sub- 

 ject in the classical writers,* the first author who in 



* Aristotle, in his ' Physicse Auscultatories ' (lib. 2, cap. 8, s. 2), 

 after remarking that rain does not fall in order to make the corn 

 grow, any more than it falls to spoil the farmer's corn when 

 threshed out of doors, applies the same argument to organisation; 

 and adds (as translated by Mr. Clair Grece, who first pointed out 

 the passage to me), " So what hinders the different parts [of the 

 body] from having this merely accidental relation in nature ? as the 

 teeth, for example, grow by necessity, the front ones sharp, adapted 

 for dividing, and the grinders flat, and serviceable for masticating 

 the food ; since they were not made for the sake of this, but it was 

 the result of accident. And in like manner as to the other parts in 

 which there appears to exist an adaptation to an end. Whereso- 

 ever, therefore, all things together (that is all the parts of one 

 whole) happened like as if they were made for the sake of some- 

 thing, these were preserved, having been appropriately constituted 



