The Descent of Man

ody and active in mind. The evil consequences,
such as they may be, of the continued preservation
of the same line of descent, without
any selection, are checked by men of rank always
wishing to increase their wealth and power;
and this they effect by marrying heiresses.
But the daughters of parents who have produced
single children, are themselves, as Mr. Galton
(12. 'Hereditary Genius,' 1870, pp. 132-140.)
has shewn, apt to be sterile; and thus noble families
are continually cut off in the direct line,
and their wealth flows into some side channel;
but unfortunately this channel is not determined
by superiority of any kind.
Although civilisation thus checks in many ways
the action of natural selection, it apparently
favours the better development of the body, by
means of good food and the freedom from occasional
hardships. This may be inferred from
civilised men having been found, wherever
compared, to be physically stronger than sava-