nearly twice as heavy as a Bosjes man, or as many an European
woman. It may be doubted whether a healthy human adult brain ever
weighed less than thirty-one or two ounces, or that the heaviest Gorilla
brain has exceeded twenty ounces.

This is a very noteworthy circumstance, and doubtless will one day help
to furnish an explanation of the great gulf which intervenes between the
lowest man and the highest ape in intellectual power;* but it has little
systematic value, for the simple reason that, as may be concluded from
what has been already said respecting cranial capacity, the difference
in weight of brain between the highest and the lowest men is far
greater, both relatively and absolutely, than that between the lowest
man and the highest ape. The latter, as has been seen, is represented
by, say twelve ounces of cerebral substance absolutely, or by 32:20
relatively; but as the largest recorded human brain weighed between
65 and 66 ounces, the former difference is represented by more than 33
ounces absolutely, or by 65:32 relatively. Regarded systematically, the
cerebral differences of man and apes are not of more than generic value;
his Family distinction resting chiefly on his dentition, his pelvis, and
his lower limbs.

([Footnote] * I say 'help' to furnish: for I by no means believe that
it was any original difference of cerebral quality, or quantity which
caused that divergence between the human and the pithecoid stirpes,
which has ended in the present enormous gulf between them. It is
no doubt perfectly true, in a certain sense, that all difference of
function is a result of difference of structure; or, in other words, of
difference in the combination of the primary molecular forces of
living substance; and, starting from this undeniable axiom, objectors
occasionally, and with much seeming plausibility, argue that the vast
intellectual chasm between the Ape and Man implies a corresponding
structural chasm in the organs of the intellectual functions; so that,
it is said, the non-discovery of such vast differences proves, not that
they are absent, but that Science is incompetent to detect them. A very
little consideration, however, will, I think, show the fallacy of this
reasoning. Its validity hangs upon the assumption, that intellectual
power depends altogether on the brain--whereas the brain is only one
condition out of many on which intellectual manifestations depend;
the others being, chiefly, the organs of