446 
Selection works by life and death, and in this case the isola 
tion for breeding purposes takes place in consequence of the 
animals peaceably separating from one another. To say 
that this is an instance of Natural Selection is very much 
like saying that a pacific agreement to divide a given region 
between two forces is a species of internecine strife. I do 
not think that the explanation would bear investigation on 
the principles of Pure Darwinism ; but if we grant that 
the process was that described by Dr. Lankester, it would 
be a selection in nature which was emphatically not 
Natural Selection. 
Another way of modifying the meaning of the phrase, 
is to treat Natural Selection as though it secured the sur 
vival of the fittest, quite irrespective of the way in which 
the variations were produced, and even as securing the 
survival of the best of those variants, which had been 
produced by transforming influences. But in this case the 
transmutation might take place apart from any principle 
of selection, and an unnecessary amount of risk to the 
survival of the race would result from the introduction of 
selection by life and death. Such modifications of the 
meaning of the phrase either testify to the existence of 
spheres in nature, in which the principle of Natural 
Selection properly .so called does not exist, or must be 
understood to mean that the Natural Selection of the 
world of nature is not the Natural Selection which is 
expounded so eloquently and so definitely in the descrip 
tions of the theory. 
“ Natural Selection,” says Dr. Weismann, “ does not 
deal with qualitative but quantitative changes in the 
individual, and the latter are always present.”* If 
this means that Natural Selection does not produce 
* Essays, vol. i., 1st ed., p. ioi.