362 



or that some of these centers may be more deeply seated than others, arid 

 for this reason less affected. 



From the foregoing, I think the following conclusions can be drawn : 



1. If we have made no mistake in locating the central Assure with 

 reference to the area of depression, this area lies mainly over the anterior 

 central gyrus of the left side and extends very slightly across the median 

 longitudinal fissure to the corresponding gyrus of the right side. 



2. The area controlling the center of the sole of each foot lies in the 

 anterior central gyrus at the margin of the median longitudinal fissure. 



3. The area controlling the hallux lies a little more lateral, perhaps 

 one-half inch, from the margin of the median longitudinal fissure. 



4. The area controlling the other toes is in close proximity to that 

 of the great toe. It may be anterior, posterior or more lateral from that 

 of the great toe. Since the region controlling the muscles of the calf lies 

 anterior, it is very probable that it is more laterally situated. This ac- 

 cords with the results of Beever and Horsley. 



5. The areas controlling the muscles of the calf on the outside and on 

 the inside of the leg, the thigh, rump and scapular regions are located in 

 the order named at greater and greater distances from the center of de- 

 pression. I have no doubt that the scapular region (possibly some others, 

 also) is only indirectly affected. 



6. Though the data are not quite sufficient to indicate accurately the 

 position of the motor centers involved, it is very probable that they are 

 arranged laterally along the anterior central gyrus from the median longi- 

 tudinal fissure in the following order : a. Center of sole of foot. b. 

 Center for great toe. c. Small toes. d. Calf muscles on lateral surface 

 of leg. e. Calf muscles on mesial side of leg. f. Thigh muscles, g. 

 Rump muscles, h. Scapular muscles. With the exception of the first- 

 named area this arrangement agrees with the results of other investiga- 

 tions. 



Leland Stanford Junior University, 

 California. 



