276 GENERAL REMARKS 



The argument from the history of the growth of the skull which 

 comes under this head cannot be given better than in the following 

 words of Gratiolet ('Bull. Soc. Anthrop. Paris/ torn. ii. Avril 18, 

 1861, p. 253): 'Chez l'enfant nouveau-ne le centre du point primitif 

 d'ossifi cation du parietal est plus distant de l'extremite occipitale du 

 crane que de son extre*mite frontale. Le cas inverse est realise* dans 

 l'adulte. On d£duit de ces faits une consequence rigoureuse, savoir 

 que dans le passage de l'enfance a l'&ge adulte les parties anterieures 

 du cerveau s'accroissent plus rapidement que les parties poste- 

 rieures. Cet accroissement marche d'arriere en avant de l'occipital 

 au frontal, il se propage comme une ondulation d'une vertebre k 

 l'autre.' 



The maintenance therefore by the part of the parietal posterior to 

 its tuberosity, a part representing its primitive centre, of a pro- 

 portion at all approaching equality with the part anterior to it is 

 a retention of infantile proportions, and pro tanto a sign of 

 inferiority. 



Mutatis mutandis a comparison of the skulls of the anthropo- 

 morpha leads us to a similar conclusion. In those apes, though the 

 lobule of the marginal convolution and the parietal eminence cor- 

 responding to it are only faintly marked ; and though the Asiatic 

 Orang is often less dolichocephalous than its African allies ; still 

 the primitive centre of ossification of the parietal bone which may 

 be supposed to hold the same relation to the subjacent brain 

 which the homologous area in the human skull is wont to do, 

 divides the bone, in all of these Simiadae, into two much more 

 nearly equal segments than is usually the case in the adult human 

 subject. 



Thus from the four points of view furnished by considering their 

 irrigation, their histological structure, their relative activity as 

 indicated by their greater amenability to the incidence of disease, 

 and their comparative anatomy, the anterior parts of the brain of 

 which we have been treating can be shown to be superior in 

 importance to those which lie posteriorly to them. The convolu- 

 tions which are curtailed in the posterior part of a brain with 

 its anterior segments relatively large are those which underlie 

 that zone of the skull which is interposed between parallel 

 lines drawn over the parietal tuberosity and over the line of the 

 lambdoid suture. Hence the importance of the two craniographical 



