158 THE ROYAL SOCIETY OF CANADA 



care, however, was taken in order to secure as accurate results as 

 possible. On studying first of all the outline of the Java skull in 

 Fig. 3 one will note what a low grade of evolution it represents. The 

 frontal region is particularly deficient. In fact this part of the 

 cranial arc looks as if it has fallen in. This depression corresponds 

 of course to the post-orbital constriction which, as noted in Section I, 

 is so well marked a feature of the Java skull when viewed from above 

 (Fig. 1). The maximum height of the skull cap of Pithecanthropus 

 erectus is only 34-3 per cent,^ that is to say, roughly one third of its 

 maximum glabella-occipital length, which compares very vividly 

 with the condition found in a recent human skull where it is usually 

 over 50 per cent, or, in other words, at least one half. As an example 

 I have chosen the calvarial height of an aboriginal Australian skull 

 which was found to be 53-3. From these figures it is an easy matter 

 to calculate that the maximum calvarial height has undergone a 

 process of evolution to the remarkable extent of 35 • 7 per cent between 

 the stages represented by the Java man-ape and the aboriginal Aus- 

 tralian skull which exemplifies the lowest group of modern hominidae. 

 Of course it must be noted that this figure merely indicates the degree 

 of heightening of the cranial roof that has taken place along one single 

 ordinate. The same figure naturally would not be expected to apply 

 to the other twenty-three ordinates. 



The red outline in Fig. 3 represents the Neanderthal skull-cap. 

 Its calvarial height index was calculated by Schwalbe^ to be 40-4 

 On comparing this with the index of the aboriginal .Australian 

 skull mentioned in the preceding paragraph it was found that 

 the evolutionary progress had been to the extent of 24-3 per cent. 

 On comparing the progress between the Java man-ape and the stage 

 of Neanderthal man it will be noted that this amounts to 15-09 per 

 cent. It is clear from this that the progress made between the Nean- 

 derthal stage and modern man has been more than half as much 

 again as that recorded between the Java man-ape stage and the 

 Neanderthal stage. For this reason one is tempted to utilise Neander- 

 thal man as an intermediate phase in cranial evolution, as his curve 

 appears to occupy the requisite position. It will, however, be demons- 

 trated presently, when we come to discuss Piltdown man, that this 

 is an entirely erroneous inference. 



On comparing the two lower outlines in Fig. 3 it will be observed 

 that the evolution of the Neanderthal skull had, at any rate, begun 

 well by making remarkably uniform progress throughout its whole 



1 As calculated by Schwalbe, Zeitschrijl fur Morph and Anth. 1899. 

 ^ op. cit. 



