6 INTRODUCTION. 



brief recapitulation of the whole work, and a few con- 

 cluding remarks. 



No one ought to feel surprise at much remaining as 

 yet unexplained in regard to the origin of species and 

 varieties, if he makes due allowance for our profound 

 ignorance in regard to the mutual relations of all the 

 beings which live around us. Who can explain why one 

 species ranges widely and is very numerous, and why 

 another allied species has a narrow range and is rare ? 

 Yet these relations are of the highest importance, for 

 they determine the present welfare, and, as I believe, 

 the future success and modification of every inhabitant 

 of this world. Still less do we know of the mutual 

 relations of the innumerable inhabitants of the world 

 during the many past geological epochs in its history. 

 Although much remains obscure, and will long remain 

 obscure, I can entertain no doubt, after the most de- 

 liberate study and dispassionate judgment of which I 

 am capable, that the view which most naturalists enter- 

 tain, and which I formerly entertained — namely, that 

 each species has been independently created — is erro- 

 neous. I am fully convinced that species are not im- 

 mutable ; but that those belonging to what are called 

 the same genera are lineal descendants of some other 

 and generally extinct species, in the same manner as 

 the acknowledged varieties of any one species are the 

 descendants of that species. Furthermore, I am con- 

 vinced that Natural Selection has been the main but 

 not exclusive means of modification. 



