No. 3.] PERIPHERAL NERVES. 665 



normal, while it was absent in the distal phalanges. It will 

 be remembered that the thumb, index, and middle fingers are 

 supplied conjointly by the median and radial. A return of 

 sensation in these fingers would therefore not give conclusive 

 evidence of median regeneration, as the impulses may have 

 been carried along the radial. Weir Mitchell long ago drew 

 attention to the fact that the index and middle fingers may be 

 flexed and the thumb opposed, to some extent at least, by 

 muscles not supplied by the median. 



In lieu of the above facts, Tillmanns would seem to express 

 himself correctly, when he states that in the above case the 

 " Motilitat " may have been vicarious. 



Gunn's case involved the grafting of a resected ulnar to the 

 accompanying median. In this case there was loss of sensation 

 and motion in the ulnar region of the hand. Eighteen days 

 after the operation, there was a slight return of the sensibility 

 along the ulnar side of ring finger, which gradually increased, 

 so that four months after the operation it was quite normal ; 

 there, was, however, no sensation in the little finger. If we 

 recall the distribution of the ulnar in the hand, it will be 

 remembered that the ring finger is supplied by this nerve only 

 on the ulnar side, the radial side receiving its innervation 

 from both the median and the radial, while the little finger has 

 no other nerve supply. The sensory impulses coming from 

 the ulnar side of the ring finger may, therefore, have been 

 carried along the median or radial. The results of Arloing and 

 Tripier, already quoted, show that this would be the case for 

 dogs. It is important to notice that there was no return of 

 sensibility in the little finger, a fact not explainable if the 

 return of sensation to the ulnar side of the ring finger is attrib- 

 uted to ulnar regeneration. The ring and little fingers could 

 not be flexed at any time after the operation, although the 

 flex. carp. ul. seemed to contract. If the explanation given 

 above is correct, the evidence in both of these cases would 

 show that regeneration of the peripheral portion of the divided 

 nerve had not taken place through the engrafted connection. 



The conclusions drawn from data obtained from the experi- 

 mental work reviewed, the clinical cases reported, and from the 



