18 DAVID HEPBURN. [No. 2. 



(2) The post-condyloid segment varied from 81 to 94 mm., 

 giving an average of 86.8 mm. or an average of 48.8 

 per cent. of the total length. 



Although none of these figures appear so highly favourable 

 to this class of skull as to the Scandinavian dolicho- and brachy- 

 cephalic sets, yet these mesocephalic skulls have distinctly gained 

 in their proportions when compared with the Australian Ab- 

 original (dolicho-cephalic) or the Sandwich Islander (brachy- 

 cephalic). Contrasted with the former, the condyle of the meso- 

 cephalic skull is 2 per cent. farther forward, and with" the latter 

 it is 1.6 per cent. farther forward. These proportions become 

 all the more striking when they are placed alongside of similar 

 anthropoid measurements. 



Thus the præ-condyloid percentage of the glabello-occipital 

 length in an adult Chimpanzee was 73.3: of a Gorilla 70: an 

 Orang-utan 65.5: of Australian Aboriginals 53.2: of brachy- 

 cephalic Sandwich Islanders 52.7: and of Scandinavians, meso- 

 cephalic 51.1; dolicho-cephalic 49.65; brachy-cephalic 49.2. 



So far as the various human skulls are concerned, the 

 peoples to whom they belonged may be said to possess the 

 erect attitude equally, and therefore the balance of the skull 

 upon the vertebral column can scarcely be the entire or only 

 determining cause of the variation in proportions. After making 

 a detailed analysis of the figures, and comparing them with 

 others obtained from young and fætal British skulls, there 

 seems every reason for concluding that the Face, in passing 

 from fætal to adult conditions, is the great determining cause 

 of the præ-condyloid and post-condyloid proportions; but as I have 

 discussed this matter in a separate paper 1 , I shall not enlarge 

 upon it here. 



The information obtained from segmenting the glabello- 

 occipital length in terms of the centre of the external auditory 

 meatus, and afterwards comparing the relative lengths of the 



1 On the Relation which the Position of the Occipital Condyles bears to 

 the Glabello-occipital Diameter of the Skull. To what is it due? (vide 

 the same number of this Journal). Hepburn. 





