XXVIT 
ON THE BRAIN OF ATELES PANISCUS 
Proceedings of the Zoological Society of London, 1861, pp. 247-260. (Read 
June 11th, 1861.) 
PLATE XNIX. [PLATE 36]. 
THE brain of a Spider Monkey (Adeles belzebuth) has already been 
partially described and figured by M. Gratiolet in his remarkable 
memoir‘ Sur les Plis Cérébraux des Primates’ (1854); but this careful 
observer had only old spirit specimens at his disposal, and it did not 
enter into his plan to give any account, either of the internal structure 
of the cerebrum, or of its relations to the cerebellum, or of the 
cerebellum itself. Hence a new description, which should touch upon 
these points, could hardly be superfluous, under any circumstances ; 
while, at the present moment, the controversy which has arisen 
respecting the nature and the extent of the differences in cerebral 
structure between Man and the Apes gives an especial value to all new 
facts. 
It has been affirmed—and a proposed new classification of the 
Mammalia has been largely based upon the assertion—that the brain 
of Man is distinguished from that of all Apes by possessing a 
posterior lobe, a posterior cornu to the lateral ventricle, and a hippo- 
campus minor—these structures being absent in all Apes, even the 
highest. ? 
I have elsewhere ? exposed the fallacy of these distinctions as ap- 
plied to the Apes in general ; Dr. A. T. Thomson 3 and Dr. Rolleston * 
1 Prof. Owen *‘On the Classification, &c., of the Class Mammalia,” Proc. of Linnean 
Society, 1857; Reade’s Lecture, 1859 ; Atheneum, March 23, 1861. 
° Natural History Review, No. 1, January, 1861; Atheneum, April 13th, 1861. 
3 Nat. Hist. Review, No. 1, January, 1861. 
§ Nat. Hist. Review, No 2, 1861. 
