THE GLENOID FOSSA IN THE SKULL OF THE ESKIMO. 
11 
opposing teeth in the upper jaw, this resulting in an oblique 
wear to the teeth constituting the central portion of the lateral 
curve of the palate. 
Again, as in the side-to-side chewing movements of the jaws, 
it is just these teeth that bear most of the sideways strain, 
it is only to be expected that a broad horseshoe type of palate 
should be practically universal in the skulls of this race. More- 
over, since it is upon the centro-lateral teeth that so much side 
strain must fall and since the first molar is usually at the centre 
of the lateral curve, it is interesting to note that in many cases 
the lingual root of this tooth is very large and divergent, this 
being evidently an adaptation to the strenuous side-to-side 
method of mastication and affording a stout, buttress-like 
support to the tooth in question. In Plate II, figures 1 and 2, 
the lingual root of the first molar will be seen projecting out 
into the palate to a remarkable extent. 
From all this evidence that I have been able to adduce, 
I think it will now be readily granted:— 
(1) That the food of the Eskimo is of an extremely tough 
nature and must need thorough mastication by very strong 
jaws. 
(2) That these people do indeed possess immensely power- 
ful jaws, and are from a very early age accustomed to make use 
of a strongly developed chewing method for the trituration of 
the tough substances constituting their ordinary diet. 
(3) That not content with the ordinary severe chewing use 
to which their jaws must be put, they regard as bonne-bouches 
substances which no ordinary jaws and teeth could make any 
impression upon; added to which the chewing power of their 
jaws is, in the case of the women, made use of in the manufacture 
of their garments from the skins of animals, etc. 
(4) That this chewing is, in the main, a widely extensive 
side-to-side movement of the mandible and reacts in varying 
degrees of intensity upon the form of their crania, mandibles, 
palates, and teeth. 
In conclusion, therefore, I think it probable that we have the 
following factors to deal with: (1) The free and extensive 
antero-rotary movements of the condyles necessary in this 
