888 MAN 



at the frontotcinporal notch where its posterior limh begins to j)ass backward 

 beneath the parietal eminence. The termination and Liltimate disposition 

 of this fissure cannot be determined. It presents a faintly nidicated anterior 

 ascendino; ramus and also a horizontal ramus extending into the frontal lobe. 

 The position of the Rolandic fissure may be estimated l:)y the general rules 

 previously applied to this sulcus in the pithecanthropus brain. The groo\-e 

 of the transverse sinus is well defined but seems open toconsiderablecriticism, 

 especially concerning its obliciuity as given in the endocranial cast. As a 

 whole, the occipito-cerebellar area is the least satisfactory region of the 

 entire cast. Subsequent studies may correct this dcliciency and produce an 

 ()ccij)ital symmetry more in keeping with this portion of the normal skull. 



THE FRONTAL LOBE OF THE DAWN ^LAN 



The frontal lobe of the Dawn man presents much less m the way oi 

 frontal impressions and juga than pithecanthropus. It offers no more con- 

 vincing indications as to the position of the Rolandic fissure. The coronal 

 constriction is much less marked than m the Ja\an man, thus showing a 

 real expansion in the frontal lobe. In one feature this area does stand out by 

 comparison. The inferior frontal convolution of the Piltdown bram is much 

 more ]3rominent than in pithecanthro[:)us. In it ari' apparent those exten- 

 sions of the Sylvian fissure so notable in connection w ith the motor speech 

 area of Homo sapiens (Fig. 381). The increased size of the frontal lobe, 

 together with the augmented prominence of Broca's speech area, is no doubt 

 indicative of a human being endowed with better linguistic abilities, broader 

 capacities for experience and improved reasoning powers. There is little 

 to denote expansion in the motor area or in the intermediate ])recentral 

 area for skilled movements. One clue to the i)robable extensions in these 

 important regions is furnished, however, by the parietal lobe which may 

 now be considered. 



