minor.

(FIGURE 20.--Drawings of the internal casts of a Man's and of a
Chimpanzee's skull, of the same absolute length, and placed in
corresponding positions. 'A'. Cerebrum; 'B'. Cerebellum. The former
drawing is taken from a cast in the Museum of the Royal College of
Surgeons, the latter from the photograph of the cast of a Chimpanzee's
skull, which illustrates the paper by Mr. Marshall 'On the Brain of the
Chimpanzee' in the 'Natural History Review' for July, 1861. The sharper
definition of the lower edge of the cast of the cerebral chamber in the
Chimpanzee arises from the circumstance that the tentorium remained in
that skull and not in the Man's. The cast more accurately represents the
brain in Chimpanzee than in the Man; and the great backward projection
of the posterior lobes of the cerebrum of the former, beyond the
cerebellum, is conspicuous.)

In many of these creatures, such as the Saimiri ('Chrysothrix'), the
cerebral lobes overlap and extend much further behind the cerebellum, in
proportion, than they do in man (Figure 16)--and it is quite certain
that, in all, the cerebellum is completely covered behind, by
well-developed posterior lobes. The fact can be verified by every one
who possesses the skull of any old or new world monkey. For, inasmuch as
the brain in all mammals completely fills the cranial cavity, it is
obvious that a cast of the interior of the skull will reproduce the
general form of the brain, at any rate with such minute and, for the
present purpose, utterly unimportant differences as may result from the
absence of the enveloping membranes of the brain in the dry skull. 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