592 



PHYSIOLOGY 



CHAP. 



that in recent years a large number of cases of true disturbance. 

 of sensibility have been published, with complete absence of heini- 

 plegic symptoms, due to extensive destructive lesions of the 

 parietal lobe, while the cortex of the precentral gyrus was intact. 

 The latter must therefore be the true motor area, as shown by the 

 experiments of Sherrington and Krause on anthropoid apes, and 

 on man by the electrical method (see Fig. 281, p. 556 ; Fig. 283, 

 p. 559). 



These recent positive cases quoted by Cox, Mills, Redlich, 



SE 



POT 



POT 



Fir.. 299. Diagram of projection and association areas. (From Flechsig.) .s'A', sensory-motor 

 area; V, visual area; A, auditory area; F, frontal association area; /, association UKM of 

 insula ; POT, parieto-occipito-temporal association area. 



Spiller, and Oppenheim, are supported by another series of older 

 negative cases, described by Bastian, Dana, Henschen, Dejerine, 

 and others, which confirm the same theory. So that from clinical 

 data we are forced to conclude with Monakow that hemiplegia 

 of cortical origin may occur without hemianaesthesia, and hemi- 

 anaesthesia, particularly with disturbance of muscular sense, 

 without true hemiplegia. Cortical hemiplegia or hemiparesis is 

 almost always associated with a lesion of the precentral con- 

 volution, and the hemianaesthesia or hemihypoaesthesia is 

 associated with lesions of the convolutions that lie behind the 

 central or Rolandic sulcus. 



Monakow, too, applied the term sensory -motor sphere to a 



