THE NERVOUS SYSTEM. 469 



principle of the soul, in the heart. But though 

 Galen thought that the rational soul resides in the 

 brain, he was disposed to agree with the poets and 

 philosophers, according to whom the heart is the 

 seat of courage and anger, and the liver the seat of 

 love 10 . The faculties of the soul were by succeeding 

 physiologists confined to the brain ; but the disposi- 

 tion still showed itself, to attribute to them distinct 

 localities. Thus Willis 11 places the imagination in 

 the corpus callosum, the memory in the folds of the 

 hemispheres, the perception in the corpus striatum. 

 In more recent times, a system founded upon a 

 similar view has been further developed by Gall 

 and his followers. The germ of Gall's system may 

 be considered as contained in that of Willis; for 

 Gall represents the hemispheres as the folds of a 

 great membrane which is capable of being unwrap- 

 ped and spread out, and places the different facul- 

 ties of man in the different regions of this mem- 

 brane. The chasm which intervenes between matter 

 and motion on the one side, and thought and feel- 

 ing on the other, is brought into view by all such 

 systems; but none of the hypotheses which they 

 involve can effectually bridge it over. 



The same observation may be made respecting 

 the attempts to explain the manner in which the 

 nerves operate as the instruments of sensation and 

 volition. Perhaps a real step was made by Glis- 

 son 12 , professor of medicine in the University of 

 10 Lib. vi. c, 8. " Cuv. Sc. Nat. p, 384. I8 Ib. p. 434. 



