298 



ANTHROPOLOGICAL SURVEY IN ALASKA 



[BTH. ANN. 4.J 



The main interest centers in the comparison of the relative pro- 

 portions of these skulls with those of the adults from the same locali- 

 ties. These comparisons, given in the smaller table, are of consider- 

 able interest. 



The cranial index is considerably higher in the children. On 

 analysis this is found to be due almost wholly to a greater relative 

 breadth of the child's skull. During later growth the Eskimo 

 cranium advances materially more in length than in breadth. A 

 further expansion in breadth is evidently hindered by some factor 

 outside of the bones themselves, for nothing appears in these that 

 could constitute such a hindrance. And the only evident outside fac- 

 tor capable of producing such an effect are the strong pads of the 

 temporal muscles. 



The mean height index ( . T , „ ) remains much the same 



b \mean of L + B/ 



in the children and adults, indicating that the relative increase dur- 

 ing growth in skull length compensates for the lagging increase in 

 breadth, while the proportion of the height to the mean of the length 

 and breadth remains fairly stable. 



The much greater growth in length than in breadth of the Eskimo 

 .skull from childhood onward is shown even better in the second part 

 of the table by a direct comparison of the mean dimensions. The 

 length of the adult skull is by over 9 per cent, the breadth by less 

 than 4 per cent, greater than that in childhood in the same groups. 



The adult Eskimo skull has also grown very perceptibly more in 

 height than in breadth, though somewhat less so than in length. The 

 result is a notably higher height-breadth index in the adult. Com- 

 pared to that in childhood the adult Eskimo skull is therefore rela- 

 tively markedly longer, higher, and narrower. 



These facts are probably of more significance than might seem at 

 first glance; for it is precisely by the same characters, carried still 

 further, that some of the Eskimo differ from others. Let us com- 

 pare two of our largest and best groups, those of St. Lawrence Island 

 and Greenland : 



The Greenland skull is longer, narrower, and somewhat higher. 

 The differences are less than those between a child and an adult 



