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. 
