tural selection; for habit, as
Darwin says, "almost implies that some benefit great or small is thus
derived."

SIMILAR EFFECTS OF NATURAL SELECTION AND USE-INHERITANCE.

Here we perceive a difficulty which will equally trouble those who
affirm use-inheritance and those who deny. Broadly speaking, the
adaptive effects ascribed to use-inheritance coincide with the effects
of natural selection. The individual adaptability (as shown in the
thickening of skin, fur, muscle, &c., under the stimulus of friction,
cold, use, &c.) is identical in kind and direction with the racial
adaptability under natural selection. Consequently the alleged
inheritance of the advantageous effects of use and disuse cannot readily
be distinguished from the similarly beneficial effects of natural
selection. The indisputable fact that natural selection imitates or
simulates the beneficial effects ascribed to use-inheritance may be the
chief source and explanation of a belief which may prove to be
thoroughly fallacious. A similar simulation of course occurs under
domestication, where natural selection is partly replaced by artificial
selection of the best adapted and therefore most flourishing animals,
while in disused parts panmixia or the comparative cessation of
selection will aid or replace "economy of growth" in causing
diminution.[45]

INFERIORITY OF SENSES IN EUROPEANS.

"The inferiority of Europeans, in comparison with savages, in eyesight
and in the other senses," is attributed to "the accumulated and
transmitted effect of lessened use during many generations."[46] But why
may we not attribute it to the slackened and diverted action of the
natural selection which keeps the senses so keen in some savage races?

SHORT-SIGHT IN WATCHMAKERS AND ENGRAVERS.

Darwin notices that watchmakers and engravers are liable to be
short-sighted, and that short-sight and long-sight certainly tend to be
inherited.[47] But we must be careful not to beg the question at issue
by assuming that the frequent heredity of short sight necessarily covers
the heredity of artificially-produced short-sight. Elsewhere, however,
Darwin states more decisively that "there is ground for believing that
it may often originate in causes acting on the individual affected, and
may thence-forward become transmissible."[48] This impression may arise
(1) from the facts of ordinary heredity--the ancestral liability being
excited in father and son by similar artificial habi