862 MAN 



Fossil Evidence in the Stldv of the Brain oi Pki hisioric Man 

 In order to gain sonu- idea ol what the hrani ot pnniitnc man was hke, 

 it is necessary to depend upon certain circLinistantial c\idence. This admis- 

 sion may seem to put the case in its most unhixoraijle hght. The hict remains 

 that the brain of man shared the same fate as other soft parts ol his body; 

 but it lias not disappeared without leaving dehnite mipressions of its size 

 and shape. These impressions ha\t' i)een found upon fossilized cranial bones 

 datmg [)ack to tfie earliest human races yet recognized. There is, of course, 

 some question as to the \alue ol such impressions m drawing conclusions 

 about the brain. Professor Symington, who has investigated the subject 

 extensively by means of endocranial casts, is e\trcmel\' cautious m the 

 matter. He prefers to admit frankly the limitations of our knowledge rather 

 than reconstruct the brain of primitive man upon too slender evidence. This 

 wise admonition has been borne in mmd throughout the lollowing descrip- 

 tions ol the prehistoric human brain. 



For the purpose of sensing the bill \alue of endocranial evidence, it is 

 important to recall that the bony capsule enclosing the brain is peculiarly 

 susceptible to the effects of cerebral growth. Some portions of this capsule 

 begin to form in cartilage and some m membrane. Four cranial bones lia\e 

 a membranous origin, i.e., the frontal, the parietal, the occipital, and 

 the sc|uamous portion ol tlu' tem|)oral bone. Expansion ol the brain appears 

 to be the dominant factor iii the growth of the head. In consecjuence, the 

 nu'iiibranous bones ol the skull bear man\ impressions ol the cerebral hemi- 

 spheres. These impressions would \x- more pronounced il tlu' ci'rebral con- 

 volutions came into actual contact w ith the iniU'r surface ol the skull. But 

 the interposition of the dura mater, the pia mater, tlu' arachnoid and the 

 cerebrospinal lluid in part obsciux's the im|:)rint ol the brain. A number ol 

 cerebral features, howex'er, art- consistently im|)ressed upon the cndocraiiium. 

 Schwalbe has shown that there are certain bon\ ridges corresponding 



