place have been detached. The base of each of the above teeth is
extended transversely, compressed antero-posteriorly, and anchylosed
to a shallow alveolus, extending obliquely across the shallower alveolar
groove. An affinity to the Lizard-tribes is manifested by the greater
development of the outer as compared with the inner wall of the
alveolar furrow.
The palatine teeth, of which there are three or four in each
palatal bone, are as large as the superior maxillaries, and are similarly
attached : the pterygoid teeth, five or six in number, which complete
the internal dental series on the roof of the mouth, are of smaller size
and gradually diminish as they recede backwards. In the interspaces
of the fixed teeth in both these bones, the places of attachment of the
shed teeth are always visible, so that the dental formula, if it included
the vacated with the occupied sockets, would express a greater number
of teeth than are ever in place and use at the same time. In the
smaller species of Boa the intermaxillary bone is edentulous.
94. Python.—The dentition of the great Java Python (Python
amethystinus) is figured, after Cuvier, at Plate 65, fig. 6 and 7.
The intermaxillary bone (a) is represented as supporting four
teeth : the superior maxillary (6) as being armed with eighteen teeth,
but of these the three which are situated on the inner side of the
anterior part of the outer row are the successors of those teeth to
which they are contiguous. No serpent has a double row of fixed
and serviceable teeth implanted on the same bone.
The palatine bone, opposite to which is the letter c in fig. 6,
supports six teeth; and the remaining eight teeth of the series are
continued upon the pterygoid bone, d. The premandibular element
of the lower jaw (fig. 7) is armed with eighteen teeth. In the tiger
Python (Python tigris) the teeth are less numerous than in the great Python.
The intermaxillary bone exhibits the places of attachment of four
teeth, but I have rarely found more than two in place : these in their
size and curvature resemble the posterior teeth of the maxillary series.
There are about twelve teeth in each superior maxillary bone, which
gradually diminish in size as they recede backwards ; the number of
sockets is eighteen. There are six sockets on each palatine bone,
and generally four teeth in place ; eight sockets on each pterygoid
bone, and five teeth in place : the mode of fixation of all these teeth
corresponds with that in the Boa constrictor. Their direction prevents
the escape of the prey in which they are once fixed ; while the separate
and independent movement of each half of both upper and lower jaw,
and of the dentigerous bones of the palate, allows of the different
series of teeth being successively withdrawn and implanted in a more
advanced position in the prey, which is thus gradually drawn into the
gullet, without the retaining force being unduly relaxed during any
part of the engulphing process.
The teeth seem to be more numerous, or there is a greater
number in place at one time in the young than the old individuals of the
Python tigris : I have counted fourteen superior maxillary and fifteen
premandibulars in place on each side of the mouth, in an individual of
this species six feet in length.
The inner alveolar border is rather higher than the outer one in
the palatine bones. The pterygoid teeth are continued along the
middle of the inferior surface or towards the outer side of those bones,
whilst in the smaller Colubriform serpents they are placed on the
inner margin of the pterygoids.
The teeth of both the Python and Boa consist of a body of firm
dentine coated by a layer of cement, which is extremely thin upon
the crown, but becomes thicker towards the expanded and attached
base of the tooth. The calcigerous tubes radiate according to the
ordinary course from the central pulp-cavity to the periphery of the
tooth : the superior and central tubes proceed in the axis of the tooth -,
those nearest to them incline outwards, deviating from the axis as
they recede from the point of the tooth, until they run at right angles
to the axis, which course they maintain throughout a great proportion
of the tooth; hence a transverse section of the tooth, as magnified in
Plate 65 b , fig. 1 , exhibits the whole length of the calcigerous tubes.
Their primary curvature is slight, with the concavity directed towards
the base of the tooth: their secondary undulations are faint and
regular through seven-eighths of their course, but the tubes become
bent in stronger and less regular sinuous curves in the rest of their
extent, where, alone, they divide dichotomously, the terminal
branches frequently inosculating in loops, the convexity of which is