strengthened or increased, they must often have seen the hairs or
feathers erected in rival and enraged males, and the bulk of their
bodies thus increased. In this case it appears possible that they might
have wished to make themselves appear larger and more terrible to their
enemies, by voluntarily assuming a threatening attitude and uttering
harsh cries; such attitudes and utterances after a time becoming
through habit instinctive. In this manner actions performed by the
contraction of voluntary muscles might have been combined for the same
special purpose with those effected by involuntary muscles. It is even
possible that animals, when excited and dimly conscious of some change
in the state of their hair, might act on it by repeated exertions of
their attention and will; for we have reason to believe that the will
is able to influence in an obscure manner the action of some unstriped
or involuntary muscles, as in the period of the peristaltic movements
of the intestines, and in the contraction of the bladder. Nor must we
overlook the part which variation and natural selection may have
played; for the males which succeeded in making themselves appear the
most terrible to their rivals, or to their other enemies, if not of
overwhelming power, will on an average have left more offspring to
inherit their characteristic qualities, whatever these may be and
however first acquired, than have other males.
_The inflation of the body, and other means of exciting fear in an
enemy_. Certain Amphibians and Reptiles, which either have no spines to
erect, or no muscles by which they can be erected, enlarge themselves
when alarmed or angry by inhaling air. This is well known to be the
case with toads and frogs. The latter animal is made, in AEsop s fable
of the Ox and the Frog, to blow itself up from vanity and envy until
it burst. This action must have been observed during the most ancient
times, as, according to Mr. Hensleigh Wedgwood,[421] the word _toad_
expresses in all the languages of Europe the habit of swelling. It has
been observed with some of the exotic species in the Zoological
Gardens; and Dr. Gunther believes that it is general throughout the
group. Judging from analogy, the primary purpose probably was to make
the body appear as large and frightful as possible to an enemy; but
another, and perhaps more important secondary advantage is thus gained.
When frogs are seized by snakes, which are their chief enemies, they
enlarge themselves wonderfully; so that if the snake be of small size,
as Dr. Gunther informs me, it cannot swallow the frog, which thus
escapes being devoured.
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