152 THE ROYAL SOCIETY OF CANADA 



breadth exhibits the relatively large increase of 18-6%, that is to say 

 twice the rate of the other. It should be noted here that Neander- 

 thal man is regarded by some biologists as a degenerative ofïshoot 

 from the main evolutionary stem, but nevertheless it is instructive 

 to make use of some of his cranial dimensions in a comparative study 

 of the evolution of the skull. On coming now to the skull of Piltdown^ 

 man it will be found that decided progress has been made especially 

 in the case of the minimum post-orbital breadth, where the increase 

 over that of the Java skull is 22-3%. Compared with this the prog- 

 ress in the evolution of the maximum parietal breadth is still slow, 

 the increase over that of the Java skull being merely 11-3%. Both 

 these figures show of course a marked advance when compared with 

 the Neanderthal skull. On investigating the corresponding dimen- 

 sions of modern Melanesian- and aboriginal Australian skulls, it was 

 ascertained that the minimum post-orbital breadth had on an average 

 increased a mere 7-4% over that of the Java skull, while the maximum 

 parietal breadth was actually slightly less (12-6 and 13 cm. being 

 the respective measurements). We thus obtain the striking in- 

 formation that the evolution of modern Melanesian and aboriginal 

 Australian skulls with special reference to both these dimensions was 

 decidedly below the stage actually reached by the Piltdown skull 

 (Fig. 2), while as regards its maximum pariétal breadth it compared 

 unfavourably even with the Java skull. Of course, it must be remem- 

 bered that in all these cases the basal height ought also to be taken 

 into account, since the evolution of the skull must necessarily 

 take place in three dimensions. Unfortunately the Java, Piltdown 

 and Neanderthal specimens are represented merely by the roof part 

 of the skull, or calvaria, so that there are no possible means of studying 

 the basal height in these cases, though one is enabled to investigate 

 the calvarial height which, as will be shown presently, furnishes us 

 with much valuable information regarding the evolution of the skull. 



^ Several reconstructions of the Piltdown skull are now in existence. It will 

 therefore be necessary to confine our attention to one of these, so as to avoid un- 

 necessary refeiences and unavoidable confusion. The only reproduction I have 

 been in a position to investigate is Smith Woodward's first model, prepared by Mr. 

 F. O. Barlow. Since my departure from London I find that Smith Woodward has 

 produced a second model of somewhat greater cranial capacity than the first; while 

 Prof. J. H. Macgregor of Columbia University and Professor Arthur Keith of Lon- 

 don have likewise prepared skilful and suggestive leproductions. My military 

 duties have prevented me from going to New York to study Professor Macgregor's 

 model. I have been able, however, to ascertain from photographs that its cranial 

 outline accords very closely with that of Smith Woodward's model. 



2 Trans, and Proc. of the Nova Scotia Institute of Science, 1917-18. 



