The shell of the ear appears to be the only part of man’s visible body
which has ceased to be useful and become purely ornamental “Persons
whose ears have been cut off hear just as well as before,” says
Professor Haeckel. Dr. J. Toynbee, F.R.S., “after collecting all the
evidence on this head, concludes that the external shell is of no
distinct use;” and Darwin was informed by Professor Preyer that after
experimenting on the functions of the shell of the ear he had come to
nearly the same conclusion.
To infer from this that our external ears have been developed, through
Sexual Selection, for purely ornamental purposes, would not be in accord
with scientific analogies. For, often as existing organs (horns,
feathers, etc.) are _modified_ for ornamental purposes, there are no
known instances of any that have been specially developed for that
purpose; even the facial muscles of expression being, as we have seen,
in this predicament. Hence we are led to conclude that man has inherited
the shell of his ear from a remote apelike ancestor, to whom it was of
use in catching faint sounds, and who consequently had the power, common
to other animals, not only of directing the ears as a whole to different
points of the compass, but of temporarily altering its shape. Indeed,
one of the strongest proofs of our descent from lower animals lies in
the fact that man still possesses, in a rudimentary form, the muscles
needed to move the ears. Some savage tribes have considerable control
over these muscles. The famous physiologist, Johannes Müller, after long
and patient efforts, succeeded in recovering the power of moving his
ears; and Darwin writes: “I have seen one man who could draw the whole
ear forwards; other men can draw it upwards; another who could draw it
backwards; and from what one of these persons told me, it is probable
that most of us, by often touching our ears, and thus directing our
attention towards them, could recover some power of movement by repeated
trials.”
Ordinary monkeys still possess the power to move their ears; but the
manlike or anthropoid apes resemble us in the rudimentary condition of
their ear-muscles; and Darwin was assured by the keepers in the London
Zoological Gardens that these animals never move or erect their ears. He
suggests two theories to account for the loss of this power: first,
that, owing to their arboreal habits and great strength, these apes were
not exposed to much danger, and thus gradually, through disuse, lost
control over these organs, just as birds on oceanic islands where they
are not subject to attacks have lost the use of their wings; secondly,
that the freedom with which they can move the head in a horizontal plane
enabled them to dispense with mobile ears.
The remarkable variability of the ears—greater, by the way, in men than
in women—is another reason for regarding them as rudimentary organs,
inherited from remote semi-human ancestors, to whom they were useful;
for great variability is a characteristic of all rudimentary organs.
Haeckel facetiously suggests that “at large assemblies, where our
interest is not sufficiently enchained, nothing is more instructive and
entertaining than a comparative study of the countless variations in the
form of the ears.” The ancient Greek artists were aware of this
variability, for Wincklemann speaks of “the infinite variety of forms of
the ear on heads modelled from life.” “It was customary with the ancient
artists to elaborate no portion of the head more diligently than the
ears.” “In portrait figures, when the countenance is so much injured as
not to be recognised, we can occasionally make a correct conjecture as
to the person intended, if it is one of whom we have any knowledge,
merely by the form of the ear; thus we infer a head of Marcus Aurelius
from an ear with an unusually large inner opening.”
If we compare a man’s ears with those of a dog or horse, differences of
shape appear no less conspicuous than differences in mobility. Two
points are especially characteristic of man—the folded upper margin and
the lobule. Our cousins, the anthropoid apes, are the only other animals
which have the margin of the ear thus folded inwards, the lower monkeys
having them simple and pointed, like other animals. The sculptor, Mr.
Woolner, called Darwin’s attention to “a little blunt point, projecting
from the inwardly-folded margin or helix.” Darwin, on investigating the
matter, came to the conclusion that these points “are vestiges of the
tips of former erect and pointed ears”; being led to think so “from the
frequency of their occurrence, and from the general correspondence in
position with that of the tip of a pointed ear.”
The lobule is still more peculiar to man than the folded margin, since
he does not even share it with the anthropoid apes, although, according
to Professor Mivart, “a rudiment of it is found in the gorilla.” An
intermediate stage between man and ape is occupied by some savage tribes
in whom the lobule is scantily developed or even absent.