84 



PEOF. G. ELLIOT SMITH OTN" 



stronger argument to oppose to those who hold that Lemurs 

 and Apes belong to separate orders, than the mere exhibition of 

 the brain of Nesopithecus. 



The Brain of Propithecus. 



When the memoir on the Prosimia]i brain was written I had 

 not seen the actual brain of any of the Indrisinse, and had to 

 draw my data from the examination of cranial casts, studied, 

 however, in the light of Milne-Edwards's descriptions of the actual 

 brains. Within the last three months Professor J. T. Wilson, 

 of the University of Sydney, has kindly placed at my disposal a 

 series of young and foetal Indrisinse labelled " Indris diadema" 

 whicli had been in spirit for a considerable time in the stores 



Fiff. E. 



SV. 



of the Australian Museum. In the oldest specimen (in which 

 the first teeth were just cutting the gums) the full complement 

 of cerebral sulci was present ; but in the rest no furrows, 

 except the hippocampal and rhinal fissures, had yet made their 

 appearance. 



I shall merely describe the arrangement of the sulci and the 

 most salient features of the largest specimen. The length of the 

 cerebral hemisphere is 31 mm., and the breadth of the two 

 hemispheres 26*5 mm. As Milne-Edwards and Porsyth Major 

 have already observed in reference to the young Propithecus, the 

 cerebellum is almost completely hidden by the cerebrum (fig B). 

 That this covering of the cerebellum is really due to an ex- 

 ceptionally great caudal extension of the cerebrum i^s shown by 



