AN HISTORICAL SKETCH 



OF THE PROGRESS OF OPINION ON 

 THE ORIGIN 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 allu- 

 sions 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 does not enter on the causes or means of 

 the transformation of species, I need not here enter on 

 details. 



*Aristotle, in his ' Physicae Auscultationes ' (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 

 Grace, who first pointed out the passage to mc), "So what hinders the dif- 

 ferent 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. 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 appro- 

 priately constituted by an internal spontaneity; and whatsoever things w;ere 

 not thus constituted, perished, and still perish." We here sec tiie principle 

 of natural selection shadowed forth, but how little Aristotle fully compre- 

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



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