612 Proceedings of Royal Society of Edinburgh. [sess. 
(a) Brachycephali : — 
(1) The prae-condyloid segment varied from 87-100 mm., 
giving an average of 92*5 mm., or an average 
of 52 *7 per cent, of the total length. 
(2) The post-condyloid segment varied from 70-97 mm., 
giving an average of 82 '7 mm., or an average 
of 47 T per cent, of the total length. 
(b) Dolichocejphali : — 
(1) The prae-condyloid segment varied from 92-108 mm., 
giving an average of 99 ‘9 mm., or an average of 
5 3 ‘2 per cent, of the total length. 
(2) The post-condyloid segment varied from 81-94 mm., 
giving an average of 87*5 mm., or an average of 
46 "6 per cent, of the total length. 
Among these brachycephalic skulls, therefore, the prae-condyloid 
segment predominated over the post-condyloid segment by 9 '8 mm., 
or 5*6 per cent, of the total length, whereas in the group of dolicho- 
cephalic skulls the prae-condyloid segment exceeded the post- 
condyloid by 12 *4 mm., or 6 -6 per cent. Thus we get an average 
difference of 1 per cent, upon the total length. In the dolicho- 
cephalic skull this was placed in front of the condyles, while in the 
brachycephalic skulls it was placed behind the condyles. 
Now, although this is apparently a small amount of difference, 
yet as an average percentage it has some importance, for it seems 
to indicate that there is a more even and equitable adjustment of 
the balanced weight of the brachycephalic skull than of the 
dolichocephalic one, which still has a certain preponderance of its 
weight falling in front of its occipital condyles, as is the case in 
the lower mammals. 
In this connection the measurements even of a few anthropoid 
skulls are extremely interesting. Thus, while in the brachycephalic 
group of human skulls the prae-condyloid segment exceeded the 
post-condyloid segment by 5 ‘6 per cent., and in the dolichocephalic 
series the difference was 6*6 per cent., in the skull of an orangutan 
the difference was 31 T per cent., in a young chimpanzee 33’9 
per cent., in a young gorilla 40 per cent., and in an adult chim- 
