But
if such a cast be made in plaster, and compared with a similar cast of
the interior of a human skull, it will be obvious that the cast of the
cerebral chamber, representing the cerebrum of the ape, as completely
covers over and overlaps the cast of the cerebellar chamber,
representing the cerebellum, as it does in the man (Fig. 20). A
careless observer, forgetting that a soft structure like the brain
loses its proper shape the moment it is taken out of the skull, may
indeed mistake the uncovered condition of the cerebellum of an extracted
and distorted brain for the natural relations of the parts; but his
error must become patent even to himself if he try to replace the brain
within the cranial chamber. To suppose that the cerebellum of an ape is
naturally uncovered behind is a miscomprehension comparable only to
that of one who should imagine that a man's lungs always occupy but a
small portion of the thoracic cavity--because they do so when the chest
is opened, and their elasticity is no longer neutralized by the
pressure of the air.
And the error is the less excusable, as it must become apparent to every
one who examines a section of the skull of any ape above a Lemur,
without taking the trouble to make a cast of it.
Pages:
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82