A laboratory manual of anthropometry / by Harris H. Wilder.

  • Wilder, Harris Hawthorne, 1864-1928.
Date:
[1920], ©1920
Catalogue details

Licence: Public Domain Mark

Credit: A laboratory manual of anthropometry / by Harris H. Wilder. Source: Wellcome Collection.

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    would seem to have some value, which future work may prove. Its angles at n and l subtend the basion-bregma height; the angles at 6 and 6a subtend the nasion-inion (Bi~B±). It is presented here merely as a suggestion. II. THE VERTEBRAL COLUMN, WITH THE RIBS AND STERNUM The Vertebral Column, with the Ribs and Sternum.—One of the most frequently emphasized differences between man and the apes is that of the degree of forward curvature of the vertebral column in the lumbar region {lordosis). This curve which, in its extreme form, is characteristic of the human back, is displayed to a much lesser degree in the Simiidae, and in the gibbons (Hylobates), the lowest of the family, is but slightly indicated. It is thus generally considered, and with much probability, that this lumbar curve has been gradual attainment in the evolution of man, and that, in all probability, the curve would be found to be less in the lower races, and thus serve as a racial criterion. The ideal and only complete method of studying this and the other curves of the vertebral column is by means of accurately made sagittal sections taken through frozen bodies, but owing to the obvious difficulties, this had been done in only a few cases, and includes only representatives of races of higher culture. Much can be done, however, by the study of the separate vertebrae, since the character of the curve is conditioned largely by the proportions of the bodies of the vertebrae involved. By measuring the antero-posterior thickness, of the lumbar centra in the median line, both clorsally and ventrally, and then comparing the two, it is found that- these parts are wedge-shaped, the most anterior one slightly, increasing gradually to the fifth, in which this character is the most pronounced. It is to this that the lumbar curve is largely due, and thus the degree of curvature may be ascertained by obtaining the above measurements of the vertebral centra. As a sufficiently exact measurement is difficult or impossible, and as the differences between the dorsal and ventral measures of single vertebrae are but slight, Turner, who first proposed this method, obtained more accurate figures by adding together the measurements obtained from twelve individual spinal columns, and comparing the sums.* Thus, the ventral measure of the 12 fourth lumbar vertebrae was 336 mm. while the dorsal measures of the same parts was only 313. In the 12 fifth lumbar vertebrae the corresponding numbers were 337 and 281, a more pro- nounced difference, since the ventral measures were practically identical, * Turner, Sir William: Report on the Human Crania and Other Bones of the Skeletons Collected During the Voyage of H. M. S. Challenger in the years 1873-76. Part ll. The bones of the Skeleton, publ. in 1886 in the Reports of the Challenger Expedition, Zoology, Vol. XVI, pp. 1-136.