12 
DARWINISM 
CHAP. 
carefully save the best seed to sow and the finest or brightest 
coloured animals to breed from, we shall soon find that an 
improvement will take place, and that the average quality of 
our stock will be raised. This is the way in which all our 
line garden fruits and vegetables and flowers have been pro¬ 
duced, as well as all our splendid breeds of domestic animals; 
and they have thus become in many cases so different from 
the wild races from which they originally sprang as to be 
hardly recognisable as the same. It is therefore proved that 
if any particular kind of variation is preserved and bred from, 
the variation itself goes on increasing in amount to an 
enormous extent; and the bearing of this on the question of 
the origin of species is most important. For if in each 
genei’ation of a given animal or plant the fittest survive to 
continue the breed, then whatever may be the special 
peculiarity that causes “ fitness ” in the particular case, that 
peculiarity will go on increasing and strengthening so Jong as 
it is useful to the species. But the moment it has reached its 
maximum of usefulness, and some other quality or modifica¬ 
tion would help in the struggle, then the individuals which 
vary in the new direction will survive; and thus a species may 
be gradually modified, first in one direction, then in another, 
till it differs from the original parent form as much as the 
greyhound differs from any wild dog or the cauliflower from 
any wild plant. But animals or plants which thus differ in 
a state of nature are always classed as distinct species, and 
thus we see how, by the continuous survival of the fittest 
or the preservation of favoured races in the struggle for life, 
new species may be originated. 
This self-acting process which, by means of a few easily 
demonstrated groups of facts, brings about change in the 
organic world, and keeps each species in harmony with the 
conditions of its existence, will appear to some persons so 
clear and simple as to need no further demonstration. But 
to the great majority of naturalists and men of science endless 
difficulties and objections arise, owing to the wonderful variety 
of animal and vegetable forms, and the intricate relations of 
the different species and groups of species with each other; 
and it was to answer as many of these objections as possible, 
and to show that the more we know of nature the more we 
