chap xii.] BRAIN OF MAN. 429 



Vertebrates ; behind this is a less conspicuous thick- 

 ening (the hippocampus major, to which is 

 added on in the higher Primates the hippocampus 

 minor. 



The average weight of the human brain is, 

 for males, between 46 and 53 oz., and for females 

 between 41 and 47 oz., but the range of difference is 

 much greater than this. As is well known, the brain 

 of Cuvier weighed 64 oz., or 4 Ibs., while that of an 

 anonymous sane man was only 34 oz., or but little 

 more than half that of the great anatomist ; but the 

 weight only must not be taken into consideration ; the 

 depth and extent of the convolutions must also be 

 estimated, and Wagner has found a difference of as 

 much as 15 per cent, in the extent of the surface of 

 the cerebral hemispheres of two selected n ales. But 

 that this, again, is not all is not only clear from the 

 consideration that a small well-made watch often 

 keeps better time than a kitchen clock, but by the 

 following facts : 



(1) The anterior portion of the cerebrum is fed by 

 the carotid and the hinder by the vertebral arteries ; 

 as the former are much larger than the latter, it 

 follows that the anterior portion of the brain is better 

 supplied than the posterior, and that pro tanto the 

 advantage lies not in the greater size of the cerebral 

 hemispheres as a whole, but in the size of the anterior 

 portion, or that which lies in front of the ear. 



(2) Though absolutely the human brain is, on the 

 average, heavier than that of all mammals except of 

 the elephant, w r hich weighs between 8 and 10 Ibs., or 

 of some whales, which may weigh as much as 5, while 

 the horse, for example, has a brain weighing only 

 23 oz., and an average-sized dog less than 7 oz., yet, 

 in the apparently more important relation of brain 

 weight to body weight, in which man presents the 

 proportions of T ^, he is surpassed by some American 



