648 



THE HIGHER ANTHROPOIDS 



of lower species. The decrease in the orbital conca\ity is unquestioiialjly due 

 to progressive expansion ol the frontal lobe. The hssural pattern ol this 

 orbital surface of tlu' frontal lobe corresponds closely to that of man, while 



FIG. 293A. BASU Ol' BRAIN, (JOKILLA. 



lAftiiiil I cn-ith I i- mm.] 



the boundary betwt'cn it and tlu' lateral surface of the luniispherc is indi- 

 cated, as in tlu' human bram, by an anterior extension of the S\ Kian fissure. 



