x THE FOEE-BKAIN 543 



such an external peculiarity, why should not other mental faculties 

 when they are markedly developed be associated with special 

 humps or prominences on the surface of the skull ? This generalisa- 

 tion gave rise to the subsequent researches, based on more or less 

 fantastic or subjective ideas, from which Gall and Spurzheim con- 

 structed the new science of phrenology. Its aims were study of 

 the most prominent mental faculties and predominating moral 

 characteristics of different individuals ; crauioscopic observation 

 of the form and varying development of the several regions of the 

 cerebral cortex ; and direct examination of the brain after death 

 in the hope of determining the seat of the different faculties. 



Although Gall was a good observer, as shown by his valuable 

 contributions to the anatomy of the brain, and although the 

 fundamental facts from which he started were correct, he lost all 

 critical sense in his eager attempt to solve his phrenological 

 problems, and accepted wholly illusory appearances for reality. 

 This did not prevent his theory, with Spurzheim's modifications 

 and additions, from obtaining a great following. 



When Floureus published his researches on the physiology of 

 the brain (1822), he conferred a great benefit on science by rooting 

 out the intruding phrenological system. 



He admitted with Gall that the cerebrum alone was of direct 

 importance to intelligence ; but absolutely rejected the, idea that 

 different regions of the cerebral cortex could be relative to different 

 intellectual functions. He found it possible to extirpate very 

 extensive portions of the cerebral hemispheres without producing 

 loss of their functions, and saw that a very small portion of the 

 brain sufficed for the exercise of its functions. But as larger 

 portions were removed all the functions became gradually weaker, 

 and were entirely lost when the destruction exceeded a certain 

 limit. Consequently the cerebral lobes must be concerned as a 

 whole in the exercise of their functions. 



When one perception is lost, he says, all the rest go too ; if one 

 faculty disappears, all the others vanish. There is therefore no 

 definite seat for the different perceptions. The capacity for 

 perceiving, judging, or willing anything is located at the same 

 place as that of perceiving, judging, willing some other thing, and 

 this faculty is therefore one, and is essentially located in a single 



organ. 



This rejection of central localisation seemed to be the last word 

 on the relations of the brain to the mind. But, as the last chapter 

 si towed, later researches into the effects of cerebral ablation in the 

 different classes of vertebrates proved that this theory, on which 

 all psychical functions are exclusively localised in the cerebral 

 hemispheres which is still maintained by Muiik and to a certain 

 extent by Loeb, does not agree with the facts, and is definitely 

 contradicted by the behaviour of the lower vertebrates after the 



