NERVOUS SYSTEM. VEKTEBltATA. 



Family SIMIID^E. 



D.644. The brain of a Hoolock Gibbon (/A//,,/,,,/,,,. /,/,-/), 

 (?). The left cerebral hemisphere has been separated 

 (figs. 243, 244). 



Fig. 243. ( X .) 



SULC. INTRAPAR. 



SULC. PAR.OCC. 



Fig. 244. ( X .) 



SULC. CENT. 



SULC. SUP. FRONT 



SULC. SUP. LIM. 



SULC, RECT. .. 



SULC.FR.ORB: 



SULC. ORB'. INS 



SULC. LAT. OCC. 



SULC. PAR. 



SULC. PAR. 



SULC. INF. OCC. 



The brain is of special interest in the Gibbons, because it 

 presents many features which may be regarded as inter- 

 mediate between those of the Anthropoid and other Apes. 



The series of modifications which would be necessary to 

 convert the brain of a Macacus into that of a SemnopitheetU 

 are carried a stage further in the case of llylobates. 



