ls which pass
their lives in the dark, as do many beetles, crabs, snails, worms, etc.

Other rudimentary organs are the wings of animals which cannot fly. For
example, the wings of the running birds, like the ostrich, emeu,
cassowary, etc., the legs of which become exceedingly developed. The
muscles which move the ears of animals are still present in man, but of
course are of no use; by continual practice persons have been able to
move their ears by these muscles. The rudiment of the tail of animals
which man possesses in his 3-5 tail vertebrae, is another rudimentary
part--in the human embryo it stands out prominently during the first two
months of its development; it afterwards becomes hidden. "The
rudimentary little tail of man is irrefutable proof that he is descended
from tailed ancestors." In woman the tail is generally, by one vertebra,
longer than in man. There still exists rudimentary muscles in the human
tail which formerly moved it.

Another case of human rudimentary organs, only belonging to the male,
and which obtains in like manner in all mammals, is furnished by the
mammary glands on the breast, which, as a rule, are active only in the
female sex. However, cases of different mammals are known, especially of
men, sheep and goats, in which the mammary glands were fully developed
in the male sex, and yield milk as food for their offspring. The
vermiform appendix of the large intestine in man, is another
illustration of a part which has no use, but in one marsupial is three
times the length of its body. The rudimentary covering of hair over
certain portions of the body, is not without interest. Over the body we
find but a scanty covering, which is thick only on the head, in the
armpits, and on some other parts of the body. The short hairs on the
greater part of the body are entirely useless, and are the last scanty
remains of the hairy covering of our ape ancestors. Both on the upper
and lower arm the hairs are directed toward the elbow, where they meet
at an obtuse angle--this striking arrangement is only found in man and
the anthropoid apes, the gorilla, chimpanzee, orang, and several species
of gibbons. The fine short hairs on the body become developed into
"thickset, long, and rather coarse dark hairs," when abnormally
nourished near old-standing inflamed surfaces.[32] The fine wool-like
hair or so-called lanugo with which the human foetus, during the fifth
and sixth months, is thickly covered, offers an