The Descent of Man

is hereditary; there is really something in it, for
the son of a celebrated seal-catcher will distinguish
himself, though he lost his father in
childhood." But in this case it is mental aptitude,
quite as much as bodily structure, which
appears to be inherited. It is asserted that the
hands of English labourers are at birth larger
than those of the gentry. (25. 'Intermarriage,' by
Alex. Walker, 1838, p. 377.) From the correlation
which exists, at least in some cases (26.
'The Variation of Animals under Domestication,'
vol. i. p. 173.), between the development
of the extremities and of the jaws, it is possible
that in those classes which do not labour much
with their hands and feet, the jaws would be
reduced in size from this cause. That they are
generally smaller in refined and civilised men
than in hard-working men or savages, is certain.
But with savages, as Mr. Herbert Spencer
(27. 'Principles of Biology,' vol. i. p. 455.) has
remarked, the greater use of the jaws in chewing
coarse, uncooked food, would act in a di-