416 TWO REMARKABLE SKULLS 



which has secured the attention it deserves onh^ within 

 recent j^ears. It is essentially a study of the degree of flat- 

 tening of the cranial roof, and would therefore naturally be 

 expected to yield most striking results. The index is usually 

 taken as the proportion which the maximum height of the 

 calvaria bears to the glabella-inion length (the line GI 

 in Fig. 4). In this Figure the calvarial height is the greatest 

 distance to the cranial roof measured perpendicularly from 

 the line GI. The index of calvarial height was found to 

 be 58.4 for No. 1 skull and 55.7 for No. 2. These results 

 when interpreted showed of course that the calvarial height 

 of both was slightly more than half the maximum cranial 

 length. In the skulls of the higher races of mankind this 

 index is, of course, always well over fifty. It is interesting 

 to compare this with the extreme degree of flattening of the 

 cranial roof of the Java man-ape, represented by an index 

 of 34. 3,^'^^^ and the flattening of the cranial arc in the Neander- 

 thal skull, represented by an index of 40.4^'''^\ Figure 4 has 

 been designed for the purpose of still further emphasising 

 the importance of this index. The curves represent the 

 antero-posterior outlines of the roofs of four skulls in the 

 sagittal plane. The line GI is the glabella-inion length 

 and from it the calvarial height was measured. The horizon- 

 tal planes of the skulls, are only approximately denoted for 

 all four, as an average had to be taken. The cranial 

 curves are all drawn to scale. The lowest curve indic- 

 ates the outline of the cranial arc of the Java man-ape. The 

 upper two cranial arcs become very definitely separated, 

 in front, the lower of the two indicating an outline of the 

 frontal part of the roof of No. (1) skull, while the upper is 

 that of an average Canadian skull taken at random for 

 purposes of comparison. The Figure demonstrates wha 

 an enormous degree of expansion the cranial roof has under 

 gone since the evolutionary stage represented by the Java 

 man-ape, and, indeed, makes one seriously question whether 



