THE BRAIN OF PREHISTORIC MAN 875 



comolLitidii. How c'\tcnsi\fly tin's region of tlir cortex in jjitlu'tantliropus is 

 proN iciecl with an iiitcrnu'diate j^reccntral area for skilled nio\-enu-nts eannot 

 1)1' (Utrrniinrd. Vhv basal surlace ol tlu' Iroiital lobe as show n \n supplemen- 

 tary reconstruction b\ Professor McGregor indicates the presi'iice of two 

 orbital conca\ities of considerable depth and well-de\eloped interorbital 

 keels; in other words, conditions lar more primiti\e and j)ithec()id than those 

 m mockrn man. 



Physiological Dedlctions to Be Dk aw x i kom Frontal Lobe. Esti- 

 mated from the jjlivsiological standpoint, the Irontal lobe of pithecanthropus 

 is indicati\e of a beha\ ioral advance lar above the plane of gorilla but 

 i'c|uall\ below that of Homo sapiens. The Ja\an man must have possessed 

 increased powers ol adapti\e reasoning. He was capable of more advanta- 

 geous adjustment than gorilla or other anthropoids. He constructed lor him- 

 self a greater sphere of experience, created at least an aj>proach to human 

 personality and dc\clo]3ed the distincti\"c characters of indi\iduality. It is 

 probable also that in his manual dcxteritx he was right-handed; at least the 

 greater size of his left Irontal lobe suggests that his brain had singled out one 

 hand as the chief representati\ c tor externalizing its activities. This in itself 

 is a distinctly human character. Around it are built many of man's most 

 productive specializations. In all ol these respects the Javan man was much 

 below his human successors. There is little in his brain by w hich to judge the 

 |3i"oricieiic\' ol his manual de\c'lopmcnt, to estimate how much skill he had 

 ac([uired with his hands. But the prominence ol his mlerior Irontal comolu- 

 tion (Fig. 375) strongly suggests that he added one supreme advantage to 

 the motor equipment of animal life. He had learned to speak — to communicate 

 in \erbal language. The gradual de\elopment of skilled acts had eventually 

 combined the elfector organs of articulation and phonation into a coordinated 

 apparatus controlled through the bram, by which he was able to express his 

 ideas and feelings. The means of communication thus established laid the 

 foundations of human know ledge. 



