14 ON THE AFFINITIES OF THE BRAIN 



with certain others, considerable value, as showing the greater 

 relative shortness of the corpus callosum. It was noticeable that 

 the anterior pair of corpora quadrigemina were less sharply marked 

 off from the posterior than in man. 



The central notch of the cerebellum was much shallower relatively 

 than in man, a point to be recollected in connexion with the rela- 

 tions stated to exist between the transverse d and antero-posterior 

 diameter c of the cerebellum. 



It is under our third head, that, namely, of the differences which 

 M. Gratiolet' s work has enabled us to describe, and we might almost 

 say to discover, that the most important points of our comparison 

 will be found. Under this head will fall the points which were 

 mentioned in Professor Huxley's article 1 , as the second and third 

 points of difference, absolutely distinguishing the brain of man 

 from that of the ape ; and under it also may be ranged those which 

 M. Gratiolet 2 lays stress upon, as indicating a relative inferiority 

 in the African to the Asiatic ape. 



To begin with ' the external perpendicular fissure.' This fissure, 

 or a part of it, is visible in Fig. i, below a ; in Fig. iii, between a 

 and a. It is well represented in most of the simious brains figured 

 by M. Gratiolet ; it may be seen in Fig. i, Fig. ii, Fig. iii, Fig. vi, 

 at / in Tab. i of Tiedemann's Icones of the brain of the Simla 

 nemestrina, Simla rhesus^ Simia sabcea, and Cebus capucinus. It 

 will be seen a little later that it is not beside the purpose to remark 

 that it may be better seen in Tiedemann's 3 figure of the brain of an 

 orang on one side than it is on either side of his representation of 

 the brain of a chimpanzee ; and that it is very well marked on both 

 sides, in a drawing of a brain of a young orang given by Professor 

 Wagner, in a work 4 written with express and constant reference to 

 M. Gratiolet's labours. Lastly, this fissure is very well seen in the 

 representation of the brain of the chimpanzee given by Professor 

 Owen in his paper in the Linnaean Society's Proceedings, January 

 21, 1857, Fig. iv, p. 19, and in his Reade Lecture, Fig. vii, p. 25. 

 The inward prolongation of this fissure is never filled up, see 16, 

 Fig. iv. It is upon the degree to which its outward prolongation is 



1 'Nat. Hist. Eeview,' No. 1, p. 83. 



2 s Memoire,' pp. 51, 62. 



3 Tiedemann, ap. Wagner, ' Icones Zoot.' Taf. viii. figs. 2 and 3. 



4 'Vorstudien zu einen wissenschaftlichen Morphologie und Physiologie des 

 Menschlichen Gehirns als Seelenorgan,' von Rudolph Wagner, Gottingen, i860. 



