on to constitution in an abstract I have made at Sclater's
request for the _Natural History Review_.[42] At the same time, there is
so much evidence of migrations and displacements of races of man, and so
many cases of peoples of distinct physical characters inhabiting the
same or similar regions, and also of races of uniform physical
characters inhabiting widely dissimilar regions, that the external
characteristics of the chief races of man must I think be older than his
present geographical distribution, and the modifications produced by
correlation to favourable variations of constitution be only a secondary
cause of external modification.

I hope you may get the returns from the Army. They would be very
interesting, but I do not expect the results would be favourable to your
view.

With regard to the constant battles of savages leading to selection of
physical superiority, I think it would be very imperfect, and subject to
so many exceptions and irregularities that it could produce no
_definite_ result. For instance, the strongest and bravest men would
lead, and expose themselves most, and would therefore be most subject to
wounds and death. And the physical energy which led to any one tribe
delighting in war might lead to its extermination by inducing quarrels
with all surrounding tribes and leading them to combine against it.
Again, superior cunning, stealth and swiftness of foot, or even better
weapons, would often lead to victory as well as mere physical strength.
Moreover this kind of more or less perpetual war goes on among all
savage peoples. It could lead therefore to no differential characters,
but merely to the keeping up of a certain average standard of bodily and
mental health and vigour. So with selection of variations adapted to
special habits of life, as fishing, paddling, riding, climbing, etc.
etc., in different races: no doubt it must act to some extent, but will
it be ever so rigid as to induce a definite physical modification, and
can we imagine it to have had any part in producing the distinct races
that now exist?

The sexual selection you allude to will also, I think, have been equally
uncertain in its results. In the very lowest tribes there is rarely much
polygamy, and women are more or less a matter of purchase. There is also
little difference of social condition, and I think it rarely happens
that any healthy and undeformed man remains without wife and children. I
very much doubt the of