A most interesting circumstance in connection with the dentition of the Australian is the comparatively frequent occurrence of a fourth molar in the jaws. We know that in European subjects the third molar or wisdom tooth is smaller, and takes longer in coming to the surface than the other molars; its development is certainly on the down-grade with our kind; but the third molar of the aboriginal is strong and lasting.
PLATE IV
1. Aluridja woman. Note matted locks and asymmetry of breasts.
2. Wongapitcha warrior, so-called Semitic type.
Even when a fourth molar cannot be found in toto, there is often present, behind the third molar, a peculiar prolongation of the alveolar groove, which seems to be indicative of a former existence, in the earlier evolutional history of the Australian, of such a tooth. Indeed, the occurrence of a fourth molar in the human species, which in the aboriginal is certainly not sporadic, must be looked upon as a character originally common to the ancestral forms of both man and anthropoid. For this reason, we must not be surprised to hear that a fourth molar might occasionally be found in any race of man.
Professor W. L. H. Duckworth has described some small dental rudiments on the alveolar surface of the upper jaw, which might even suggest remnants of third premolars. Such rudiments usually occur between the second bicuspid and the first molar, and consist of dentine. If it can be proved that we have before us true evidence of immature tooth-development, the phenomenon suggests a dental formula similar to that of some of the simians possessing three premolars. On the contrary, the formations may be the remnant masses of temporary milk teeth.
Supernumerary bicuspids are, it appears, not very often observed in the Australian.
It is still questionable whether, as Charles Darwin suggested, the ancestor of the human species has ever possessed extra large eye-teeth or canines in any way resembling those of an anthropoid. In the Talgai skull, referred to later, the canines certainly seem abnormally large, but one could not be expected to draw definite conclusions from a single specimen, especially when it is known that, even among ourselves, we here and there see persons whose canines are quite the same size as those of the Talgai fossil.