The Descent of Man

many facts shew how easily the skull is thus
affected. Ethnologists believe that it is modified
by the kind of cradle in which infants sleep.
Habitual spasms of the muscles, and a cicatrix
from a severe burn, have permanently modified
the facial bones. In young persons whose
heads have become fixed either sideways or
backwards, owing to disease, one of the two
eyes has changed its position, and the shape of
the skull has been altered apparently by the
pressure of the brain in a new direction. (84.
Schaaffhausen gives from Blumenbach and
Busch, the cases of the spasms and cicatrix, in
'Anthropological Review,' Oct. 1868, p. 420. Dr.
Jarrold ('Anthropologia,' 1808, pp. 115, 116)
adduces from Camper and from his own observations,
cases of the modification of the skull
from the head being fixed in an unnatural position.
He believes that in certain trades, such as
that of a shoemaker, where the head is habitually
held forward, the forehead becomes more
rounded and prominent.) I have shewn that