TROGLODYTES NIGER, THE CHIMPANZEE 



573 



1(1 the sprciali/at ion ot t lu' upper r\trriiiit\ and hand. The Inlliix ol sensory 

 stinudi IS undouhtedl\ greater Irom this part ol the l)od\ tlian Irom the 

 lower extri'initv. A greater ck'<j;rec oi S|jeeiah/.at ion is manliest in the hand, 



FK;. 2jj. DOKSAL SL KIACF. Ol BKAIN STEM, CHIMPANZEE. 



lActii.il Lt-ntitli 4H min.l 



Key to Diacram. n. m. fis., Dorsonuclian I-issurc; n. m. sept., Dorsomedian St'pnim; sui>. cer. ped., 



Superior CVrcbclI:ir Pi'dunclc; r. t., Tuberculuni Trigcniini. 



lorearni and ami tlian in the le^. Takiii<^ into aeeount its relation both to 

 loeoniotion and to the iiianx feats of manual de\terit\- ol whieh the chim- 

 panzee is eupablc, the hand seems to lill a more important olliee than the 

 foot. 



In the \ tntrieiilar portion of the dorsal surlaee ol the oblongata, the 

 eharaeteristit- di\eruenet' occurs in tiie alar plates, tiius disclosing the floor ol 

 the \-entriele. The lateral walls of this inferior angle of the fourth \entricle 

 iiiv lormed as elsewhere b\ tlu' iiiiineiices ot the clava and eun(.'us. The ela\a 

 does not exteiul as far cephalad as does the ciineus. Both ol these eminences 



