THE GLENOID FOSSA IN THE SKULL OF THE ESKIMO. 3 



of the glenoid cavity ; he writes: "The form of the glenoid cavity 

 .... bears an intimate relation to the dentition of the animal 

 and the nature and extent of the movement of the jaws. Thus 

 in a child it is nearly flat with no well marked surrounding ele- 

 vations, its axis is transverse and little rotary motion is made 

 use of. In the adult it is deeply sunk, the axis of the condyle 

 is oblique and rotary movements are largely made use of in 

 triturating food. In the felidae it is strictly transverse, their 

 teeth adapted for slicing but not grinding, would gain nothing 

 by lateral motion, which is rendered quite impossible by the 

 manner in which the long transverse condyles are locked into the 

 glenoid cavity by strong processes in front and behind . . in 

 Herbivora the condyle is roundish, the ascending ramus long, 

 the pterygoid muscles large and the glenoid cavity shallow. 

 In the whale, which of course does not masticate at all . . the 

 articulation is reduced to a mere ligamentous attachment." 

 Here, then, I think we have the key to our problem, and that 

 we shall find that it is to some differences in the method and ex- 

 tent of mastication that is due the distinction in the form of the 

 glenoid fossae between civilized and primitive man. Since, 

 therefore, in the Eskimo we have a race which seems most 

 uniform in the display of glenoid flattening, we will take them 

 as the champions of the "shallow-glenoid" type, and examine, 

 first, the conditions of their life and the nature of the food they 

 have to masticate, and, secondly, the form of the masticatory 

 apparatus presented in their skulls. 



Now it is well known that the staple diet of the Eskimo is 

 of a more or less purely animal nature, fish, flesh, and fowl being 

 their main means of subsistence, while, to judge from all accounts, 

 much of the meat they eat must be of a very tough nature; 

 so that, on the whole, we could not find any other race of the pres- 

 ent day in which there would be so much need for strong jaws, 

 and so much need too to use them in such a manner that their 

 food should be thoroughly triturated before being swallowed. 

 A few extracts from the writings of authors who have lived 

 among and studied the Eskimos will perhaps be of use to em- 

 phasize my point, and give confirmation to my statement as 

 to the nature of the Eskimo's food. 



