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OF THE LOWER-JAW. O
from the Coronoide Process of one side, to that of the other, (g)
In both Jaws they are every where relatively proportional to the
; being thicker behind, Avhere the Teeth are larger, (h) and
Teeth
more irregular, upon account of the more numerous fangs in-
serted into them.(t) The Teeth that are situated backwards, in

(g) [Unbroken continuity of the alveolar series inbotb jaws is amongst
existing Mammalia only to be found constantly in Man. In the highest
genus of the Quadrumana {Troglodytes), there is a considerable diastema
or interspace between the canine and lateral incisor in the upper jaw, and
usually a smaller interval is present between the canine and anterior
premolar in the lower. In the larger species of Orang {Pithecus Satyrus),
a corresponding wide interval exists between the upper canine and the
contiguous incisor ; in the lower jaw the occurrence of a diastema is
not constant. In one specimen of the smaller species of Orang
(Pith. Morio), described by Professor Owen, the upper jaw exhibited
the ordinary diastema; but in a second specimen it was absent, and the
teeth were as uninterrupted as in the human subject. In both specimens,
the implantation of the teeth in the lower jaw was continuous. In
Pithecus Morio, the occasional absence of interval in the alveolar series
would appear to depend on the large size of the teeth, which equal
those of the Great Orang and the small relative proportions of the
maxillae. In Man, the constant continuity of the alveolar series is
evidently associated with the equable length of the teeth, the shortness
of the jaws, and the small size of the cuspidati. In the Great Apes, when
the mouth is closed, the long crown of the laniary is lodged in the
corresponding interspace between the teeth of the opposed jaw. The
value, however, of this as a peculiar characteristic of Man is diminished
by the discovery of a similar unbroken proximity of the teeth in some
extinct Quadrupeds ; e.g., Anoplotherium, Nesodon, Dichodon. (1)]
(h) [The alveoli in Man increase regularly in size from the incisors to
the true molars. In the Anthropoid Apes, the largest socket is that for
the great canine tooth.]
(i) [In the greater number of skulls of the Australo-Tasmanian variety
of Man, and in some skulls of African Negroes, especially of those in-
habiting the Western Coast, the alveoli of the grinding series will be
found of great relative breadth. This thickness of the molar alveoli in
these races is dependent on the large size and complex implantation of
the corresponding teeth.]

<1) Owen, Transactions of the Zool. Soc. ; Art. "Teeth,'' Todd's Cyclopedia
of Anatomy ; Quarterly Journal of the Geol. Soc, February 184S.