TROGLODYTES NIGER, THE CHIMPANZEE 561 



in doubt, the chim])aii/(.'c's ha\r a way of scratchintj; the surlacf nl {\\v body, 

 especially the aims, breast and the upper ]3ortion ol the thigh. They seem 

 to ha\e a eertaiu degree ol understanding among lliemsel\es whieli eon\-eys 



FIG. 25 IB. DETAILED DIAGRAM OF DORSAL SURFACE OF BRAIN, CHIMPANZEE. 



Key to Diagram, obl.. Oblongata; sul. interpar., Sulcus Interparietalis; sulc. i-r. sup.. Sulcus Fron- 

 talis Superior; SULC. pr. sup.. Sulcus Precentralis Superior; sulc. ret. inf.. Sulcus Retrocentralis Inferior; 

 s. R. s.. Sulcus Retrocentralis Superior. 



the meaning not only ol emotional distaste, but also of delinite desues and 

 urges whether directed tow ard another of the same species or toward other 

 creatures or objects. 



