166 THE HISTORY OF CREATION. 
their thick and strong hairs than the individuals of the first 
generation. If this process is continued for several genera- 
tions in one and the same locality, there will arise at last 
such an increase of this characteristic, such an increase of 
the hairs on the surface of the leaf, that an entirely new 
species seems to present itself. It must here be observed, 
that in consequence of the interactions of all the parts of 
every organism, generally one individual part cannot be 
changed without at the same time producing changes in other 
parts. If, for instance, in our imaginary example, the number 
of the hairs on the leaves is greatly increased, a certain 
amount of nourishment is thereby withdrawn from other 
parts; the material which might be employed to form 
flowers or seeds is diminished, and a smaller size of the 
flower or seed will then be the direct or indirect consequence 
of the struggle for life, which in the first place only pro- 
duced a change in the leaves. Thus the struggle for life, in 
this instance, acts as a means of selecting and transforming. 
The struggle of the different individuals to obtain the 
necessary conditions of existence, or, taking it in its widest. 
sense, the inter-relations of organisms to the whole of their 
surroundings, produce mutations of form such as are pro- 
duced in the cultivated state by the action of man’s selection. 
This agency will perhaps appear at first sight small and 
insignificant, and the reader will not be inclined to concede 
to the action of such relations the weight which it in reality 
possesses. I must therefore find space in a subsequent 
chapter to put forward further examples of the immense 
and far-reaching power of transformation exhibited in ~ 
natural selection. For the present I will confine myself to 
simply placing side by side the two processes of artificial 
