952 



THE CENTRAL NERVOUS SYSTEM 



nervous system. But care and judgment are necessary on the part of 

 the operator, and although as a rule there is no difficulty in putting an 

 end to the condition by a suitable suggestion, it is said that in rare 

 instances grave mischances have occurred. There seems to be no ground 

 for the opinion that women are more easily hypnotized than men. Out 

 of more than a thousand persons, Liebault found only seventeen abso- 

 lutely refractory. 



SECTION XII. SIZE OF BRAIN AND INTELLIGENCE CIRCULATION 

 IN AND RESUSCITATION OF CENTRAL NERVOUS SYSTEM AFTER 

 ANAEMIA CHEMISTRY OF NERVOUS ACTIVITY CEREBRO-SPINAL 

 FLUID. 



Relation of Size of Brain to Intelligence. While it is the case 

 that some men of great ability have had remarkably heavy and 

 richly convoluted brains, it would seem that in general neither great 

 size nor any other obvious anatomical peculiarity of the cerebrum 

 is constantly associated with exceptional intellectual power. In 

 the animal kingdom, as a whole, there is undoubtedly some relation 

 between the status of a group and the average brain development 

 within the group. But that this is a relation which is complicated 

 by other circumstances than the mere degree of intelligence is 

 sufficiently shown by the fact that a mouse has more brain, in pro- 

 portion to its size, than a man, and thirteen times more than a horse ; 

 while both in the rabbit and sheep the ratio of brain-weight to body- 

 weight is nearly twice as great as in the horse, in the dog only half 

 as great as in the cat, and not very much more than in the donkey. 

 The following tables, too, which illustrate the weight of the brain 

 in man at different ages, show that, although we might give ' the 

 infant phenomenon ' an anatomical basis, we should greatly over- 

 rate the intellectual acuteness of the average baby if we were to 

 measure it by the ratio of brain to body- weight alone. 



Brain-weight. 

 1,045 g rm 

 1,315 



1,168 

 1,286 



1-505 

 1-336 

 1,414 



BlSCHOFF. 



HUSCHKE. 



