430 



Mr. W. P. Herringkam. 



No. of case. 



14. 



15. 



23. 



42. 



43. 



52. 



53. 



54. 



Digital 

 branches. 



1 



2... 



3 



t 



5 



6 



6 



6 



6 



6 

 6 

 6 



7,8 + 9 



6 

 6 

 6 

 7 

 8 



6 

 6,7 

 6,7 



8 

 8,9 



6 

 6,7 

 7 

 7 



8 



j>6 + 7 



6 + 7,8 



8 



H 



8 + 9 | 



The origin of the ulnar nerve was traced in thirty-two cases, of 

 which fourteen were adult. 



It was found to arise in four different ways. Its most common 

 origin is from the 8th and 9th together. This occurred in twenty- 

 three cases, eleven foetal and twelve adult. With these is sometimes 

 combined a strand from the 7th, as shown in five cases, four foetal 

 and one adult. In three foetal cases it arose from the 8fch only, and 

 in one foetal, and one adult case from the 7th and 8th. The 7th is 

 only added to the nerve in some of those cases where it gives a branch 

 to the inner cord. In several cases the branch from the 8th was 

 much larger than that from the 9th. I have never seen the reverse. 



The nerve was split down in seven instances, of which two were 

 foetal. One of these had fibres of the 7th in it which, however, were 

 not traced separately. Branches were traced to the muscles of the 

 forearm from both nerves in five cases, in two from the 8th alone. 

 The anterior cutaneous branches were in four cases from the 9th, in 

 one apparently from the 8th. The dorsal cutaneous was in all seven 

 a branch of the 8th. The superficial division in the hand going to 

 the fingers was traced in all, and in three contained fibres from both 

 8fch and 9th, in the other four was wholly from the 9th, while the 

 deep or muscular branch traced in six was in five wholly from the 

 8th, and in the sixth received also from the 9th. 



According then to these dissections the 8th and 9th usually both 

 supply the forearm muscles, the 8th gives the dorsal cutaneous, and 

 serves the intrinsic muscles of the hand, while the 9th gives sensation 

 to the skin on the palmar surface of the hand, and of the lower third 

 of the forearm. 



The origin of the internal cutaneous was noted twenty-three times 

 in my dissections. Nine times it contained a fibre from the 8th as 

 well as the 9th, fourteen times it sprang from the 9th alone. In two 

 cases of the former class the 8th was separated from the 9th in the 

 nerve. In the one the 9th alone supplied the skin of the arm, the 

 8th not entering the skin until below ; in the other the 9th was seen 

 to supply the skin of the arm and of the front of the forearm, while 

 the 8th ran to the back of the forearm. 



