This is a measurement of much value, both alone and as a supplement to the cranial index, for skulls with the same index may be high or low and thus really of a radically distinct type.
The height of the vault is best studied in its relation to the other cranial dimensions, particularly to the mean of the length and breadth, with both of which it correlates. But in the Eskimo it is also of interest to compare the height with the breadth of the skull alone. The former relation is known as the mean height index and the latter as the height-breadth index. Both mean the percentage value of the basion-bregma height as compared to the other dimensions.
The mean height index H
(Mean of L+B) advocated independently by the writer since 1916 (Bull. 62, Bur. Amer. Ethn., p. 116), is proving of much value in differentiation of types and has already become a permanent feature in all writers' work on the skull. There is a corresponding index also on the living.
In the American Indian the averages of the index range from approximately 76 to 90. (See Catalogue of Crania, U. S. Nat. Mus., Nos. I and II.) Where the series of specimens are sufficiently large the index does not differ materially in the two sexes. Indices below 80 may be regarded as low, those between 80 and 84 as medium, and those above 84 as high.[153]
The southwestern and midwestern Eskimo skulls show mean height indices that may be characterized as moderate to slightly above medium. In general the broader and shorter skulls show lower indices, approaching thus in all the characters of the vault the Mongolian skulls of Asia. (Compare Catalogue Crania, U. S. Nat. Mus., No. I.) The Indian Point, St. Lawrence Island, and Little Diomede Island skulls are again, as with the cranial index, very close together, strengthening the evidence that the three constitute the same group of people. (Pls. 59, 60.)
The northwestern Eskimo and most of those of the northeast have relatively high vault. Barrow and Point Barrow are once more almost the same. The Point Hope group shows a high vault, though also rather broad. The somewhat broad Hudson Bay crania are but moderately high, like those of the southwestern Eskimo. The northern Arctic skulls give smaller height than would be expected with their type; the Southampton Island specimens give higher. The old Igloo group from near Barrow stands again close to Greenland; its skull is even a trace narrower and higher, standing in both respects at the limits of the Eskimo. The whole, as with the cranial index, shows evidently a rich field of evolutionary conditions.
| Southwestern and midwestern | |
|---|---|
| (11) | |
| Togiak | 81.8 |
| (25) | |
| Nelson Island | 82.1 |
| (6) | |
| Southwest Alaska | 82.3 |
| (6) | |
| Pilot Station, Yukon | 82.3 |
| (10) | |
| Mumtrak | 82.5 |
| (13) | |
| Hooper Bay | 82.7 |
| (116) | |
| Nunivak Island | 83.3 |
| (5) | |
| Chukchee | 83.3 |
| (34) | |
| Pastolik and Yukon Delta | 83.4 |
| (4) | |
| Port Clarence | 83.4 |
| (29) | |
| Indian Point (Siberia) | 83.8 |
| (279) | |
| St. Lawrence Island | 84.1 |
| (12) | |
| Little Diomede Island | 84.5 |
| (14) | |
| St. Michael Island | 85.1 |
| Northwestern | |
| (69) | |
| Barrow | 83.8 |
| (99) | |
| Point Barrow | 84.1 |
| (2) | |
| Kotzebue Sound and Kobuk River | 84.4 |
| (20) | |
| Shishmaref | 84.5 |
| (33) | |
| Wales | 85.0 |
| (216) | |
| Point Hope | 85.7 |
| (4) | |
| Golovnin Bay—Cape Nome | 85.9 |
| (51) | |
| Igloos, southwest of Barrow | 86.3 |
| Northern and northeastern | |
| (7) | |
| Hudson Bay and vicinity | 82.2 |
| (15) | |
| Northern Arctic | 82.7 |
| (33) | |
| Baffin Land and vicinity | 84.4 |
| (9) | |
| Smith Sound | 85.1 |
| (101) | |
| Greenland | 85.1 |
| (15) | |
| Southampton Island | 85.5 |
The height-breadth index (H×100)
(B) of the Eskimo skull shows in substance the same conditions as did the mean height index, but while less informative or dependable on one side, on the other it accentuates the relative narrowness of the skull in some of the groups.
BUREAU OF AMERICAN ETHNOLOGY FORTY-SIXTH ANNUAL REPORT PLATE 59
