1 82 Charles Darwin. 



tory. Although much remains obscure, I can enter- 

 tain no doubt, after the most deliberate study and 

 dispassionate judgment of which I am capable, that 

 the view which most naturalists entertain, and which 

 I formerly entertained — namely, that each species 

 has been independently created — is erroneous. I 

 am fully convinced that species are not immutable ; 

 but that those belonging to what are called the same 

 genera are lineal descendants of some other and gen- 

 erally extinct species, in the same manner as the 

 acknowledged varieties of any one species are the 

 descendants of that species. Furthermore, I am 

 convinced that natural selection has been the main 

 but not exclusive means of modification." 



It will be seen, then, that the various forms of na- 

 ture, animal or vegetable, are continually changing, 

 affected by the conditions or circumstances which 

 surround them, and that evolution is the term ap- 

 plied to the change. 



