SIMIA SATYRUS, Till- ORANG-OUTANG 



489 



and cMTor lasting tor a period of owr two weeks, quite unexpectedly one 

 morning seemed to get the idea of w hat was exjx'eted of him and responded to 

 llie test withuLit a single mistakt'. lit- had seemed to soKe the problem sud- 



MG. 223B. DETAILED DI A(;RAM OF DORSAL SURFACE OF BRAIN, 



ORANG-OUTANG. 

 Key to Diagram, sulc. fr. med.. Sulcus Frontalis Mcdius; suLC. occ, Sulcus Occipitalis (Inferior); sulcus 

 i>RECENTRALis INF., Sulcus Proccntralis Inferior; suix. retrc. inf.. Sulcus Retroccntralis Inferior; s.R.s., 

 Sulcus Retroccntralis Superior. 



denlv and in all probal)ilIt\ , ideat ionallx . The eurve of learning plotted irom 

 the daily wrong ehoicc's of the animal, had it been obtained Irom a human 

 subject, would undoubtedl\ ha\c- been described as ideational, possibly 

 even as rational, for its sudden drop from near the maximum to the base 

 line strongly suggests, if it does not actually prove, the presence of insight. 

 Never before has a cur\f of learning like this been obtained Irom an inira- 



