304 St. J. Brooks, 



flame of a lamp or gas jet until the skin was burnt, for the amuse- 

 ment of his comrades". 



The difference between Létiévant's case and the one which I exa- 

 mined appears to indicate that in the one patient the crossing of the 

 radial and ulnar nerves was very slight and that in the other it was 

 considerable. 



Case 2 was a man of about 40 years of age in whom the ulnar 

 and median nerves had been divided just above the wrist by an acci- 

 dent which occurred in February, 1875. Sensation was impared but 

 nowhere completely lost. The loss of sensibility was more marked on 

 the palmar than on the dorsal surface of the fingers, the maximum 

 anaesthesia being on the palmar surfaces of the little finger and ulnar 

 half of the ring finger. An inspection of the diagram (fig. 4) suggests 

 the probability that either the radial nerve or the external cutaneous 

 branch of the musculo-spiral crossed as far as the little finger in this 

 case and that the amount of distribution of the ulnar nerve on the 

 back of the hand was small. 



It appears from the above facts that the sensory effects of section 

 of a nerve, e. g. the ulnar, may vary considerably, a) .The amount of 

 skin affected is much greater in some patients than in others (compare 

 the above case — Case 1 — with Létiévant's). b) The degree of loss 

 of sensibility is subject to considerable differences (compare Dr. Jencken's 

 case, in which sensibility was entirely lost, with Létiévant's cases, in 

 which a certain amount of sensation always persisted). These differ- 

 ences in the clinical facts find a ready explanation in the greater or 

 lesser degree of intercrossing of the nerves which has been already 

 described. 



That great differences exist in the distribution of the grosser 

 branches of the radial and ulnar nerves on the dorsum manûs, has 

 long been known ; Henle *) represents the normal arrangement as fol- 

 lows; — the little and ring finger and the ulnar half of the middle 

 finger as supplied by the ulnar and the other two and a half digits 

 by the radial; Krause's 2 ) account is substantially the same, but he 

 is inclined to give the radial nerve a larger share in the innervation 



*) Op. cit p. 550. 

 2 ) Op. cit. p. 896. 



