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 centre-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 



