Edinger, The Sig7iificance of the Cortex. 75 



ment in those animals which depend much on this sense, while 

 in the case of the apes and man these parts occupy a subordi- 

 nate place. 



It is not necessary to rehearse in this circle the evidence 

 that the cortex with its numerous cells and fibre tracts is essen- 

 tially the bearer of the psychical functions. Comparative anat- 

 omy and Goltz's experiments show that its existence is not 

 necessary for the so-called lower functions which take place 

 without constant intervention of the intelligence and were 

 formerly called instinctive. Schrader, by his experiments on 

 doves and lizards has obtained results like those I reached on an 

 anatomical basis and the experiments of Steiner have not offered 

 any contradiction. 



If the cortex is non-essential for the above functions, it by 

 no means follows that it has no influence upon them, and at 

 this point the results obtained by experimenters who have em- 

 ployed localization, offer a valuable supplement. It must be 

 assumed that, in fact, a chart of the surface of the brain may be 

 constructed, a chart which indicates at which points stimuli may 

 be applied to produce a specific motor or sensory reaction upon 

 the deeper centres. There is no contradiction between the two 

 experimental tendencies, but one supplements the other. Goltz, 

 however, shows that the removal of the cortex and its connec- 

 tions deprives the animal of the organ for all those functions 

 which make possible the higher psychical manifestations, such as 

 intelligence and reflection. 



In progressive paralysis of insanity we meet clinically and 

 anatomically a disease from focal beginnings which gradually 

 destroys the cortex. The final result is just what Goltz obtained 

 operatively, the patient becomes deeply imbecile. Naturally 

 the symptomatic complex is greatly modified in man, who has 

 become accustomed in his activities to permit the cooperation of 

 memory and and reflection to a very great extent. Thus man 

 bears cortical injuries much worse than animals and reacts from 

 injuries which would hardly permanently affect a dog at all, 

 to the extent of complete obliteration of function. Moreover 

 the clinical symptoms of paralysis, so far as these questions are 



