In the southwest and midwest the upper alveolar arch is relatively (as well as absolutely, barring one group) somewhat broad and short. This may be in correlation with the broader head in this area, just as the absolutely slightly longer palates over the rest of the Eskimo territory and particularly (in males) in the northeast may correlate with the longer heads in those regions. This point may be tested on our splendid material from St. Lawrence Island. Taking the broadest and the narrowest skulls from this locality, the following data are obtained for the proportions of the upper dental arch:
| Males | Females | |||
|---|---|---|---|---|
| Narrowest skulls (C. I. 70.7-73.5) | Broadest skulls (80.6-83.1) | Narrowest skulls (70.3-74.2) | Broadest skulls (80.9-83.8) | |
| Length | 5.68 | 5.58 | 5.52 | 5.20 |
| Breadth | 6.83 | 6.77 | 6.66 | 6.36 |
| Index | 83.2 | 82.4 | 82.9 | 82.7 |
| Mean diameter | 6.26 | 6.18 | 6.09 | 5.78 |
| Mean cranial diameter (cranial module) of same skulls | 15.61 | 15.49 | 14.97 | 14.73 |
| Percentage relation of mean dental arch diameter to the mean diameter of the skull | 40.1 | 39.8 | 40.7 | 39.2 |
| Length of same skulls | 19.21 | 18.10 | 18.35 | 17.25 |
| Percentage relation of length of dental arch to that of skull | 29.5 | 30.8 | 30.1 | 30.1 |
The above figures show several conditions. The first is that the arch is quite distinctly larger in the narrow than in the broad skulls in both sexes. The second fact is that the skull (vault) itself is slightly larger in the narrow-headed. The third is that the length of the arch is somewhat greater in the narrow and long skulls than it is in the broad and shorter, relatively to the skull size. The fourth is that there appears a close correlation, more particularly in the females, between the length of the arch and that of the skull.
FOOTNOTES:
[155] See Bull. 62, Bur. Am. Ethn., and writer's Report on an Additional Collection of Skeletal Remains from Arkansas and Louisiana, published with Clarence B. Moore's report on the Antiquities of the Ouachita Valley, Philadelphia, 1909.
THE BASION-NASION DIAMETER
The anterior basal length (basion-nasion) is a measurement of importance, though its full meaning in anthropology is not yet entirely clear. From data quoted by Martin (Lehrb., 715-716) it appears to average in whites up to 10.3 centimeters in males and up to 10.1 centimeters in females, and is known to correlate closely with the length of the vault. Secondarily it also correlates with stature.
Data on American Indians are not yet generally available, though in preparation. The Munsee skulls gave the writer for the diameter the means of 10.27 for the males and 10.02 for the females; the mound skulls from Arkansas and Louisiana gave 10.45 for the males and 9.77 for the females.
An abstract of the data on the Eskimo skulls is given in the next table. The values for the measurement are rather high, especially for such short people. The percentage relation of the measurement to the length of the skull appears also to be high. Manouvrier (1882, quoted in Martin, Lehrb., 716) found this relation in French skulls to be 53.6 in the males and 54.7 in the females.