in the number, situation, and direction
of the teeth, &c. These are
a few of the differential elements
which separate man from the quad-
rumana, and the various genera
and species of the latter from each
other. But the chief value of these
osteological differentia lies in their
perfect applicability to man, and
the facility with which they enable
us to distinguish between the various
human types. Thus, in the
best developed and most intellectual
races, the supra-orbital ridge
is smooth, well carved, and not
much developed; as we descend
towards the lower types, it becomes
more and more marked, until, in
* the African and Australian heads,
5 it has attained its maximum deÎ
velopment. In the Orang, this
5 feature begins to assume a greater
importance, while in the Chimpanzee;
its enormous size renders it a
characteristic mark. Here, then,
is the evidence, to some extent, of
gradation, in a seemingly exclusive
ethnographic mark, whose significance
is elucidated by a resort to
anthropology. Again, it is curious
to observe how certain adult animal
characters appear in man during
the foetal period only. Thus, in
some mammals, as the Bodentia
and Marsupialia, we find, as a permanent
feature, an inter-parietal
hone. In man, the occipital hone
consists, at birth, of four parts,
which are not consolidated until
about the fifth or sixth year.
Each of these parts is developed
from distinct ossific centres. Eor
the posterior or proral portion, an