Franz, Sensations Folloivtng Nerve Division. 



231 



experiments to give these sorts of sensations with the extremes of 

 temperature. On the upper part of the forearm simihxr results were 

 obtained. In this case the subject was permitted to keep his eyes 

 open and to mark with his other hand the places where the stimuli 

 changed in quality. The marking of the division between the areas 

 was not clear and distinct, but between two points, about two centi- 

 meters apart, the difference in the sensations was reported to be 

 marked. These results are in accord, therefore, with those of stimula- 

 tion of the individual square centimeters and they strengthen the 

 impression that the sensation difference that was reported in the 

 first series was not due to radiation or conduction. These results 

 are quite unlike the results in normal individuals, for in the latter 



Ficx. 6. 

 Fig. 6. — Area insensitive to cold stimuli, compared with the loss of pressure 

 sensations. Area insensitive to cold inclosed within heavy line. Area marked 

 with vertical lines insensitive to pressures. 



we find the most intense sensations at the places where the warm 

 or cool object leaves the skin, and the intermediate area appears to 

 be stimulated uniformly with the same temperature. 



On the hand, experiments similar to those on the arm were made, 

 but with not so many different temperatures. The results of these 

 experiments are given in Figs. 6 and 7. In Fig. 6 is shown the area 

 of the hand insensitive to cold stimulation. This included the ulnar 

 quarters of the palm and the back of the hand, the whole of the 

 fourth and ring fingers, the first two joints of the second and index 

 fingers and about half of the thumb. For comparison, the area in- 

 sensitive to pressure with a pencil is illustrated on the same diagram 



