LOCALIZATION IN THE CAT. 

 By C. L. Herrick. 



An operation, performed in connection with Mr. E. G. 

 Stanley, which it is hoped to describe in full in a subsequent 

 issue, perhaps deserves notice on account of its suggestiveness 

 upon points raised in Munk's last paper in the Proceedings of 

 the Berlin Academy. ^ 



Munk states that in the dog and monkey the region for the 

 extremities is concerned with the formation of tactile and press- 

 ure sensations and perceptions of the limbs of the opposite side. 

 The tactile reflex is also located in this region and is completely 

 lost when it is extirpated. In addition to this, this region is at 

 least chiefly responsible for the pain sensations of the members; 

 pain is dependent for its perception up to a certain degree of in- 

 tensity on this region, and complete extirpation of the region 

 nearly destroys tlie sense of pain which may gradually be gained 

 by substitution of other regions. Again, there is a connection 

 between the cortical centre and the reflex centre for the limbs, 

 and that which inhibits the reflexes. 



After removal of these areas the animal moves awkwardly, 

 lifting the feet too high or too little, placing them irregularly so 

 that the feet double under. There is a tendency for the feet to 

 slip laterally from the body permitting the body to fall toward 

 the side opposite the operation. These irregularities disappear, 

 so far as su])erficial observation goes, completely. 



The feet corresponding to the operation lose their respon- 

 siveness to slight tactile irritation. When a strong pressure is 

 brought to bear there is reflex response, i. e. movement of the 

 limb, but no evidence of sensation, as is proven by the fact that 

 the head is not turned toward the irritated member as it is to- 

 ward any other. 



1 . Ueber die Fuehlsphseren der Grosshirnrinde. Mittheilungen au.s den Sltz- 

 uugsb. d. Koenigl. Preus. Akad. der Wissenschaftcn zu Berlin. .Tiily, 1892. 



