232 STUDIES IN LIFE AND SENSE, 



of the convolutions of the brain is to largely increase the amount of 

 its grey matter relatively to the space in which the organ of mind is 

 contained ; whilst the perfect nutrition of the brain is also thus 

 provided for through its convoluted structure permitting a fuller 

 distribution of the minute bloodvessels which supply the brain with 

 the vital fluid. It is a very noteworthy fact that the structure of the 

 grey matter differs materially from that of the white. In the grey 

 matter nerve-cells are found in addition to nervous y#ra > . The ceils 

 originate nervous force, whilst the fibres are simply capable of con- 

 veying this subtle force. Thus it may be said that it is in the grey 

 matter that thought is evolved, and from this layer that purposive 

 actions spring. The white matter, on the other hand, merely conveys 

 nerve-force and nervous impressions, and is thus physiologically 

 inferior in its nature to the grey substance. 



The observations of Gratiolet, Marshall, and Wagner seem to 

 leave no room for doubt that the convolutions of the brain increase 

 with culture, and are therefore more numerous and deeper in civilised 

 than in savage races of men. It is curious, however, to observe that 

 certain groups of quadrupeds are normally " smooth-brained," and 

 possess few or no convolutions. Such are rats, mice, and the rodents 

 or " gnawing " animals at large. It can hardly be maintained that 

 in these animals intelligence is normally low or instinct primitive 

 although, indeed, the just comparison of human with lower instincts 

 must be founded on a broader basis than is presented by this single 

 anatomical fact. 



A final observation concerning the anatomy of the brain relates 

 to its size and weight as connected with the intelligence. The phre- 

 nological doctrine of the disposition of faculties must be held to 

 include the idea, that the larger the brain, the better specialised 

 should be the mental qualities of the individual. The greater the 

 amount of brain-substance forming the good and bad qualities and 

 regions of the phrenologist, the more active should be the mental 

 organisation. Now, it is a patent fact that this rule tells strongly 

 against the phrenologist's assumption. True, various great men have 

 had large brains ; but cases of great men possessing small brains are 

 equally common, as also are instances where insanity and idiocy were 

 associated with brains of large size. The normal average human 

 male brain weighs from 49 to 50 ounces; man's brain being 10 per 

 cent, heavier than that of woman. Cuvier's brain weighed 64^- 

 ounces; that of Dr. Abercrombie 63 ounces; that of Spurzheim, of 

 phrenological fame, 55 ounces; Professor Goodsir's brain attained a 

 weight of 57^ ounces ; Sir J. Y. Simpson's weighed 54 ounces ; that 

 of Agassiz 53 '4 ounces ; and that of Dr. Chalmers 53 ounces. As 

 instances of high brain-weights, without corresponding intellectual 

 endowment, may be mentioned four brains weighed by Peacock, the 



