The Descent of Man

tend beyond the extremity of the ischial tuberosities,
it seems as if the tail originally had
been bent round by the will of the animal, into
the interspace between the callosities, to escape
being pressed between them and the ground,
and that in time the curvature became permanent,
fitting in of itself when the organ happens
to be sat upon." Under these circumstances it is
not surprising that the surface of the tail should
have been roughened and rendered callous,
and Dr. Murie (93. 'Proceedings Zoological Society,'
1872, p. 786.), who carefully observed
this species in the Zoological Gardens, as well
as three other closely allied forms with slightly
longer tails, says that when the animal sits
down, the tail "is necessarily thrust to one side
of the buttocks; and whether long or short its
root is consequently liable to be rubbed or chafed."
As we now have evidence that mutilations
occasionally produce an inherited effect (94. I
allude to Dr. Brown- Sequard's observations on
the transmitted effect of an operation causing