1905.] THE OCCIPITAL CONDYLES. 5 



which are respectively in front of, and behind, an imaginary line 

 projected from the anterior border of the occipital condyle so as 

 to intersect the glabello-occipital diameter at right angles. It is 

 not necessary to emphasise the fact that the glabello-occipital 

 diameter of a skull does not always occur at the same posterior 

 point in different skulls. It is sufficient for my purpose that 

 this diameter is the greatest length of each skull, since my 

 object is to show how much of this length occurs in front of, 

 and behind the position of the occipital condyles. In the course 

 of this investigation the following skulls have been measured: 

 (a) SCANDINAVIAN, dolichocephalic, 12; brachycephalic, 5; 

 mesocephalic, 5; (b) AUSTRALIAN ABORIGINAL, dolicho- 

 cephalic, 12; (c) SANDWICH ISLANDERS, brachycephalic, 12; 



(d) ANTHROPOID APES, Orang-utan, 1; Gorilla, 1; Chim- 

 panzee, 2 (1 adult, 1 young); Gibbon (Hylobates Mulleni), 2; 



(e) BRITISH, young and fcetal, 8. The Scandinavian crania 

 were kindly lent to me by Professor Guldberg of the University 

 of Kristiania, Norway, and for the others I am indebted to the 

 kindness of Principal Sir William Turner and Professor Cun- 

 ningham of Edinburgh. In the accompanying Table the results 

 of these measurements are given, reduced to average percentages 

 of the average total length for ease of comparison. 



If the discussion were confined to the adult skulls, we should 

 note that the figures indicate a steady progression, and that the 

 præcondyloid segment showed a steady reduction of its per- 

 centage, while there was a corresponding increase in the per- 

 centage of length belonging to the post-condyloid segment. 

 Further, it is clear that there is considerable variation in the 

 amount of the two percentages among the anthropoid apes. 

 Again among the savage and civilised crania there are con- 

 siderable variations in the amounts of the percentages, apart 

 from the distinct differences discoverable when the savage and 

 civilised are contrasted with each other. This is all the more 

 note-worthy when we remember that many of these skulls fall 

 into the same group as classified upon their cephalic indices. 



A glance at the proportions of the two segments in the skull 



