CRANIOLOGY OF PEOPLE OF INDIA. 715 



millimetres as would represent the thickness of the bone of the cranial vault at the 

 points of measurement. 



The greatest length and breadth, along with the collective measurements of the 

 height radii from the basion to the vault, expressed the diameters of the skull in the 

 dimensions of length, breadth and height. In the fourteen male Dravidians the sum 

 of these dimensions showed a range of variation from 778 to 903 mm. The two 

 extremes were exceptional, and the other crania ranged from 824 to 895, the mean 

 being 863-4 mm. Some anthropologists have considered that an approximate estimate 

 of the internal capacity of the skull can be obtained from the external dimensions of 

 length and breadth, along with one radius of height. It ought, however, to be kept in 

 mind that the curve of the vault of the cranium in any plane is not a segment of 

 a sphere, but varies in its degree of curvature, more especially when the height is 

 measured in the living head from the auditory meatus, or in the skull from the basion. 

 An estimate based on such measurements cannot, I consider, adequately express the 

 cranial capacity. I have given in Table IV. the sum of five radii from the basion for 

 the collective height, which, along with the greatest length and breadth, more com- 

 pletely embodies the three dimensions, in which, however, the thickness of the bones 

 of the vault is included. For purposes of comparison this Table includes the actual 

 capacity of the crania obtained by the method described many years ago in my 

 Challenger Report (1884), the merits of which have been confirmed by subsequent 

 experience in the cubage of hundreds of crania. The sum of the external dimensions, 

 however, does not bear a constant relation to the actual capacity as determined by 

 the method of cubing, but varies in some cases from about l^ths, in others f ths, and 

 in others -fths of the actual cubic capacity. 



In previous memoirs, more especially those on the crania of the Tasmanians,* I have 

 drawn on the tracings of the sagittal contours the chords of the frontal, parietal, and 

 occipital arcs ; I have also erected a perpendicular from each chord to the most prominent 

 part of the arc of each bone, so as to measure the greatest projection of each arc. 



The same practice has been adopted in the study of the male Dravidian skulls, 

 and the results are recorded in Table V. 



The nasio-bregmatic chord varied in this series of crania from 97 to 115 mm., the 

 mean being 109. The bregma-lambdal chord in one skull was only 99, in four 120, 

 and in one 122, the mean being 112. The lambda-inial chord was the shortest ; in four 

 crania it was below 60, in only three did it reach from 70 to 7&, and the mean was 64. 

 In considering the length of the perpendicular drawn from each chord to the most 

 projecting part of its arc, the thickness of the bone at that spot is included with the 

 corresponding diameter of the cavity. When the contour had been obtained in a skull 

 sectionally made, as in the Gond skull No. 1, the thickness of the frontal bone at the 

 bregma-nasal perpendicular was 10 mm., which, subtracted from the length, 28 mm., of 

 that line, left 18 mm. for the perpendicular in the corresponding part of the cranial 



* Trans. Roy, Soc, Edin,, vol. xlvi., part ii., 1908, and vol. xlvii., part iii., 1910. 



