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92 HUNTER ON THE TEETH.
body, with one sharp angle turned forwards and outwards, the
other backwards and inwards ; besides they have three fangs,
which diverge, and terminate each in a point ; these are almost
connate ; and, in a specimen in the Museum of the Great Northern
Hospital, which has fallen under the Editor's observation, a similar
peculiarity is to be noticed
; in these cases, the first premolar presented
the usual implantation by three fangs. In the lower jaw in these great
Apes, the first premolar, when viewed externally, appears much larger
than the second in the Chimpanzee it is twice the size, in the Gorilla
;
three times the size, of the same tooth in Man. Its crown is somewhat
of a three-sided figure, the anterior and outer angle being produced
forwards, and making an approach in this respect to the peculiar
characteristic of the first premolar in the Baboons. It is surmounted by
two trihedral cusps
; of these, the outer is the larger and higher, whilst
the inner is feebly developed on a ridge extending transversely from the
outer cusp. A thick basal ridge belts the inner and posterior part of
the crown. The second lower premolar is of a four-sided figure. Its
two cusps are placed on the anterior half of the upper surface of the
crown ; they are united by a transverse ridge, and a third smaller cusp
is developed on the inner and posterior angle. Each lower premolar is
implanted by an anterior and posterior fang ; of these, the former is the
larger. They are divergent, and compressed antero-posteriorly. In the
Orangs (Pithecus), we recognise the same complex implantation of the
premolars, by three fangs in the upper, and by two in the lower jaw.
The first premolar in the upper jaw differs from the same touth in the
Gorilla and the Chimpanzee, in having the anterior external angle of
the base produced, an approximation to the configuration observed in
the lower Quadrumana. The outer lobe of this tooth is a little larger
than the inner one in
; the second upper premolar, both lobes are
equal. The two cusps of the first are also more developed than the two
cusps of the second. In the lower jaw, the outer cusp of the first pre-
molar attains by far the greater dimensions ; from it three ridges pro-
ceed—one to the front part of the grinding surface, one to the back part,
and a third transversely inwards, where it developes a small tubercle.
In the second lower premolar, the inner tubercle attains almost an equal
size with the outer. Amongst the distinguishing features of the true
molar teeth in Man, are their large size in proportion to the jaw, and in
proportion to the other teeth, and the rounded contour of their grinding
surfaces. In the upper jaw, the two first teeth of the molar series are
quadricuspid. Of the four cusps, the antero-internal one is the largest
and it is connected with the postero-external by a low ridge, on either
side of which is a deep groove, extending on the outer side to the middle
of the outer surface, on the inner side to the inner surface. The con-
nection of the inner anterior and the outer posterior cusps by the
92 HUNTER ON THE TEETH.
body, with one sharp angle turned forwards and outwards, the
other backwards and inwards ; besides they have three fangs,
which diverge, and terminate each in a point ; these are almost
connate ; and, in a specimen in the Museum of the Great Northern
Hospital, which has fallen under the Editor's observation, a similar
peculiarity is to be noticed
; in these cases, the first premolar presented
the usual implantation by three fangs. In the lower jaw in these great
Apes, the first premolar, when viewed externally, appears much larger
than the second in the Chimpanzee it is twice the size, in the Gorilla
;
three times the size, of the same tooth in Man. Its crown is somewhat
of a three-sided figure, the anterior and outer angle being produced
forwards, and making an approach in this respect to the peculiar
characteristic of the first premolar in the Baboons. It is surmounted by
two trihedral cusps
; of these, the outer is the larger and higher, whilst
the inner is feebly developed on a ridge extending transversely from the
outer cusp. A thick basal ridge belts the inner and posterior part of
the crown. The second lower premolar is of a four-sided figure. Its
two cusps are placed on the anterior half of the upper surface of the
crown ; they are united by a transverse ridge, and a third smaller cusp
is developed on the inner and posterior angle. Each lower premolar is
implanted by an anterior and posterior fang ; of these, the former is the
larger. They are divergent, and compressed antero-posteriorly. In the
Orangs (Pithecus), we recognise the same complex implantation of the
premolars, by three fangs in the upper, and by two in the lower jaw.
The first premolar in the upper jaw differs from the same touth in the
Gorilla and the Chimpanzee, in having the anterior external angle of
the base produced, an approximation to the configuration observed in
the lower Quadrumana. The outer lobe of this tooth is a little larger
than the inner one in
; the second upper premolar, both lobes are
equal. The two cusps of the first are also more developed than the two
cusps of the second. In the lower jaw, the outer cusp of the first pre-
molar attains by far the greater dimensions ; from it three ridges pro-
ceed—one to the front part of the grinding surface, one to the back part,
and a third transversely inwards, where it developes a small tubercle.
In the second lower premolar, the inner tubercle attains almost an equal
size with the outer. Amongst the distinguishing features of the true
molar teeth in Man, are their large size in proportion to the jaw, and in
proportion to the other teeth, and the rounded contour of their grinding
surfaces. In the upper jaw, the two first teeth of the molar series are
quadricuspid. Of the four cusps, the antero-internal one is the largest
and it is connected with the postero-external by a low ridge, on either
side of which is a deep groove, extending on the outer side to the middle
of the outer surface, on the inner side to the inner surface. The con-
nection of the inner anterior and the outer posterior cusps by the
