THE CEREBRUM 585 



also, careful studies have failed to show any impairment of sensibility. On 

 the other hand, destruction of the post-central convolution in monkeys by 

 the electro-cautery and in man by disease has invariably led to a loss of sen- 

 sibility, hemianesthesia, on the opposite side of the body without at the 

 same time causing any loss of motion. The location and extent of the an- 

 esthesia corresponds, of course, with the location and extent of the lesion of 

 the cortex. 



, Gushing has recently recorded the results of stimulation with the electrical 

 current of the post-central convolution in two conscious patients. The local- 

 ized stimulus gives rise to definite sensations which were likened in one 

 case to a sensation of numbness, and in the other to a definite tactual im- 

 pression. From the foregoing facts it may be stated in a general way that 

 the post-central convolution is the region for tactile (light touch) and asso- 

 ciated forms of sensation such as tactile discrimination and localization and 



FIG 2 m THE AREAS AND CENTERS OF THE MESIAL ASPECT OF THE HUMAN HEMICEREBRUM.- 



(C. K. Mills.) 



perhaps of the finer shades of temperature, in other words of epi-critic 



Tn^Musde Sense Area.-The area of muscle sensibility has been assigned 

 to the region posterior to but adjoining the post-central convolution am 

 includes the anterior part of the super-parietal and sub-paneta j 

 volutions and perhaps the supra-marginal convolution on he latera 

 aspect and a portion of the callosal convolution on the mesial aspe 



sSS^ich are evoked in response to the action of nerve 

 impulses coming from tendons, muscles, etc are those o passive po^ ion 

 and the direction and duration of movements of parts of the body. 

 ^J*dpt-m findings indicate that lesions of this area are 

 ol ^owed by a loss of the muscle sense. Owing to the close juxtaposi ion 

 of the areas of cutaneous and muscle sensibility it is unusual to find a loss 



