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III. " On the Posterior Lobes of the Cerebrum of the Quadru- 

 mana." By WILLIAM HENRY FLOWER, Esq., F.R.C.S., 

 Conservator of the Hunterian Museum, Royal College of 

 Surgeons. Communicated by Dr. SHARPEY, Sec. U.S. 

 Received November 20, 1861. 



(Abstract.) 



The substance of this paper is contained in one presented to the 

 Society June 20th, 1861 (see Abstract in 'Proceedings, 'vol. xi.p. 37G), 

 with which further observations since made have been incorporated. 

 A more detailed description of the posterior lobes of the brain of 

 CercopithecuSy Macacus, and Celus is given, as well as an account of 

 the same parts in Presbytes and Ilapale. It is shown that the brain 

 of the last-named and that of Man, placed at the opposite ends of an 

 extensive series, present in the posterior lobes certain well-marked 

 common characters, but that in the Marmoset this portion of the 

 brain is proportionally more elongated, the calcarine fissure is more 

 deeply cut, the hippocampus minor more prominent, and the posterior 

 cornu patent to a greater extent. 



The author having had an opportunity of dissecting the brain of 

 a Lemur in a recent condition, has substituted a description of the 

 cerebral characters of this animal for that of the Galago previously 

 given, which having been long preserved in spirit, was not so well 

 adapted for the purpose. In possessing a well-marked Sylvian fis- 

 sure, a median lobe, a calcarine sulcus, and in the general character 

 of the convolutions, the brains of members of this family are evidently 

 formed upon the type common to the brain of Man and the higher 

 families of Quadrumana ; but while the gradations of this type are 

 tolerably regular and unbroken between Homo and Hapale, the 

 Lemurs do not follow in the same line of degradation, and should rather 

 be placed as a small subseries parallel to the lower part of the large 

 series, but separated from it by the shortness of the posterior lobes, 

 large size of the olfactory bulbs, and inferior characters of the cere- 

 bellum. 



A Table is added, showing the comparative length of the posterior 

 lobes in certain Quadrumana and other Mammalia, measured upon 

 a plan described in the paper. 



