The Descent of Man

epilepsy in guinea-pigs, and likewise more recently
on the analogous effects of cutting the
sympathetic nerve in the neck. I shall hereafter
have occasion to refer to Mr. Salvin's interesting
case of the apparently inherited effects of motmots
biting off the barbs of their own tail- feathers.
See also on the general subject 'Variation
of Animals and Plants under Domestication,'
vol. ii. pp. 22-24.), it is not very improbable that
in short-tailed monkeys, the projecting part of
the tail, being functionally useless, should after
many generations have become rudimentary
and distorted, from being continually rubbed
and chafed. We see the projecting part in this
condition in the Macacus brunneus, and absolutely
aborted in the M. ecaudatus and in several
of the higher apes. Finally, then, as far as
we can judge, the tail has disappeared in man
and the anthropomorphous apes, owing to the
terminal portion having been injured by friction
during a long lapse of time; the basal and
embedded portion having been reduced and