NATURAL SELECTION INSUFFICIENT TO DEVELOPMENT OF MAN. 15 
agency employed in the determination of their actual variety. 
Other methods and other forces may have conspired with it* 
checked or thwarted it, in the work of educing from one common 
form the boundless multiformity which now meets our eyes. 
No doubt the whole course of Mr. Darwin’s reasonings and 
illustrations leads us to the conviction that in his judgment 
the unassisted action of natural selection is sufficient to pro- 
duce all the necessary modifications, but so far as express words 
go, he has not excluded — at any rate in the passage which I 
have quoted — the possibility of the co-operation or interference 
of some other cause ; and it is important to call attention to 
this, because a very high authority on this subject, Mr. A. B. 
Wallace — the independent originator, and the most able de- 
fender of the theory which bears Mr. Darwin’s name-— has 
recently proclaimed his conviction that natural selection by 
itself is inadequate to the production of at least one, and that 
the most important, form of life. In other words it is im- 
possible, in Mr. Wallace’s opinion, that man can have been 
developed from the inferior animals by the process of natural 
selection alone. Whatever else it may have done, it is un- 
equal to this, the great and crowning act of creative power.* 
To understand his reasonings we must first get a clear idea 
of what the doctrine of natural selection is. It does not imply, 
as many will persist in assuming, any capacity in the individual 
to alter his own structure, and adapt himself to surrounding 
circumstances. The individual does not materially change. 
Such as he is born, such, in his physical structure, he will 
remain to the end of his life. Only if his physical structure 
does not happen to be well adapted to the circumstances in 
which he finds himself, his life will be a short one. His 
neighbour, who happens, by some small variation, to be 
slightly better adapted to those circumstances, will live longer. 
And, moreover, since the offspring inherit the parents’ pecu- 
liarities, the descendants of this latter are likely to prevail to 
the exclusion of those of the former ; and thus, in the course of 
some generations, the prevailing type and character of the 
whole family will be slightly modified. It is not the indivi- 
dual, but the collection of similar individuals, or the Kind — a 
word which may be usefully employed to avoid the technical 
meaning attaching to class or species — that changes. And it 
changes only by means of changing its units, by dropping out 
from time to time those that are unsuitable, and keeping in and 
preserving those that are suitable. In this way it adapts itself 
* See u Contributions to the Theory of Natural Selection.” (Macmillan 
& Co.) By A. B. Wallace. This paper is little more than an expansion 
of part of the argument in one of these Essays. 
