578 



POPULAR SCIENCE MONTHLY. 



dexes between 75 and 80 are characterized as mesocephalic. The 

 two skulls in our illustrations, viewed from above, show how 

 marked the differences in these proportions may be. In very rare 

 instances the index may run in individuals as low as 62, and it 

 has been observed as high as 103 that is to say, the head being 

 broader than it is long. In our study, which is not of individuals, 

 but of racial groups, the limits of variation are of course much 



DoLiCHo - cephalic: 

 Index 70 



BRACflY - CEPHALIC 



Index 57 



^fter 

 Tlcun, 



JJfterTlaTiKe 



less. We shall seldom find heads in any considerable numbers 

 exceeding the limits roughly indicated by the two crania in our 

 illustrations.* 



A factor which is of great assistance in the rapid identifica- 

 tion of racial types is the correlation between the proportions of 

 the head and the form of the face. In the majority of cases, par- 

 ticularly in Europe, a relatively broad head is accompanied by a 

 rounded face, in which the breadth back of the cheek bones is 



* Our data are drawn in the main not from the relative proportions of each type of head 

 occurring within a given area, but from general averages made up by including all head 

 forms alike. The more scieutific method would be to give the relative proportions of each 

 type of head ; but that is impossible witli the present data. It is a comforting circum- 

 stance, however, that the results drawn from the average approximate closely enough to 

 those obtained in the other way for all general purposes. Oftentimes, for lack of data, it 

 is impossible to employ the more scientific method for detailed analysis. Anthropologists- 

 distinguish between the relative proportions of the head measured over all the soft tissues,, 

 giving the cephalic index, and those taken from the skull divested of all its fleshy parts, in 

 which latter case the relation of length to breadth is expressed by the so-called cranial 

 index. Experience has shown that the cephalic generally exceeds the cranial index by twa 

 units, more or less. In other words, the living head is relatively broader than the cranium 

 by about three per cent. This would fix our extreme indices on the living head at about 

 1'i and 89 for averages. 



