AN HISTORICAL SKETCH 



DF THE PROGRESS OF OPINION ON THE ORIGIN 



SPECIES, 



PREVIOUSLY TO THE PUBLICATION OF THE 

 FIRST EDITION OF THIS WORK. 



I will here give a brief sketch of the progress of opin- 

 ion on the Origin of Species. Until recently the great 

 .najority of naturalists believed that species were immut- 

 able 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-exist- 

 ing forms. Passing over allusions to the subject in the 

 classical writers,* the first author who in modern times 

 has treated it in a scientific spirit was Buffon. But as his 

 opinions fluctuated greatly at different periods, and as he 



* Aristotle, in his ^Physicae 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 organization; 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 other parts in which there appears to exist an adaptation 

 to an end. Wheresoever, therefore, all things together (that is, all the 

 parts of one whole) happened like as if they were made for the sake of 

 something, these were preserved, having been appropriately constituted 

 by an internal spontaneity; and whatsoever things were not thus con- 

 stituted, perished and still perish." We here see the principle of natu- 

 ral selection shadowed forth, but bow little Aristotle fully comprehended 

 the principle, is shown by his remarks on the formation of the teeth. 



