Academt or Sciences] 

 No. 3] 



Jk 



MEASUREMENTS 



Cephalic Index 



41 



— . SO XoC »i 

 • • - 2.5 (Dtet CUw*M.e«uw* at tftA^e 



so much hindrance to the expansion of the vault in the lateral direction. This is probably of but 

 small account in the ordinary adidt skull; but the studies on the old Americans have shown that, 

 in the mentally active at least, the skull keeps on enlarging slightly to a much later age than the 

 mere setting in of the adult period; 28 and there is thus a chance that the development and use 

 of the temporal muscles may more or less influence the breadth of the skull through a consider- 

 able part of the life of an individual. What influence the pressure of the muscles in question has 

 on the breadth of the skull during the growing period has long since been strikingly demonstrated 

 by Anthony. 29 



HEAD HEIGHT INDICES 



These indices attempt to show the relative value of the height of the head to the other two 

 principal head diameters. The older indices are those of height-length and height-breadth, and 



» The Old Americans, p. 186 et seq.; and especially Growth During Adult Life, Proc. Am. Philos. Boo., 1936, LXXVI, 875 et seq. 

 !B Anthony (R.). — Etudes experimentales sur la morphogenie des os: modifications craniennes consecutives a l'ablation du crotaphyte chez le 

 chien. J. physiol. & path, gen., Paris, 1003, V, 245-258. 



