10 ON THE AFFINITIES OF THE BRAIN 



mark of serial elevation. Cumulatively, it may have weight ; 

 absolutely, it can have none. The second canon is but a converse of 

 the first ; and expressed in similar language, it may run thus : — 

 If certain structures, or certain relations of certain structures, 

 are found to exist in animals confessedly higher in the scale 

 of life than those which are the subjects of comparison, such struc- 

 tures, or such relations of such structures, cannot by themselves be 

 held to be marks of serial degradation. Cumulatively, they may 

 be of weight ; absolutely, they are not. These canons have been, 

 perhaps necessarily, expressed in complex language ; in themselves, 

 however, they are sufficiently simple and self-evident, and being so, 

 are compatible with either view of the origin of species. 



The first of these canons we have already applied, in our com- 

 parison of the overlapped cerebellum of the lower monkeys with the 

 partially unoverlapped cerebellum of our orang. The even curve 

 described by the boundary line of the superior surfaces of the Bush- 

 woman's brain, as given by M. Gratiolet in the first plate appended 

 to his often-quoted work, and the anteriorly and posteriorly taper- 

 ing ends of the hemispheres there figured, enable us to apply the 

 second canon to the several marks of degradation spoken of, as 

 diminution of upward and of lateral growth in the frontal and the 

 occipital lobes. The even, regular curve 1 indeed of the skull, and 

 its narrowing, tapering frontal and occipital regions, as seen in the 

 lower races, would have led us to anticipate some such cerebral 

 conformation as the unhappily all but unique specimen of such a 

 brain as the one just referred to actually discloses to us. 



The foramina for the nerves in the skulls of the lower races of 

 mankind have been said by certain ethnologists 2 to present larger 

 diameters than the similar foramina in the basis of the skull of 

 higher races ; and if this be really the case, our first canon will 

 come to apply to our ninth point of difference, the larger relative 

 sizes, namely, of the nerves in the simious brain. 



The three points of diminution in downward development of the 

 posterior lobes, and in both downward and in antero-posterior de- 



1 ' Hunterian Osteological Catalogue,' 5346, 5755. See, also, ' Symbolik der Mensch- 

 lichen Gestalt,' von C. G. Carus, p. 1 70, fig. 34. 



2 Prichard, ' Phys. History,' vol. i. pp. 294, 296, 302 ; Lawrence in description of 

 Negro skull ; and ' Phil. Trans.' 1836, p. 517, which I had not seen when I wrote this. 

 But Tiedemann, citt. Prichard, ' Phys. Hist.' ii. 352, says the nerves of the Negro are 

 not larger relatively to his brain than those of Europeans. 



