432 



Mr. W. P. Herringham. 



by the 7th, yet by a nerve which is of lower origin than the first 

 subscapular. Thus in four instances, three of them adult, where the 

 first subscapular came from the 5th alone, the second contained no 

 5th, and in these cases the lower part of the muscle was supplied by a 

 lower nerve. This confirms also three other adult dissections of the 

 first subscapular. In one it was triple ; the first twig going to the 

 upper fibres of the muscle ran from the 5th, the next to the middle 

 fibres from the 5th and 6fch, and the third from the 6th alone, below 

 which came a twig from the second subscapular. In the two other 

 cases the nerve was double, the upper twig coming from the 5th, the 

 lower from the 6th root. 



The third subscapular going to the latissimus dorsi was traced in 

 forty-two cases. Once it came from the 5th and 6th alone, three 

 times it was formed by the 7th and a branch from the undivided 5th 

 and 6th, four times by the 7th and a branch from the 6th (once with 

 an addition from the 8th also), twenty-one times from the 7th alone, 

 and thirteen from both 7th and 8th. 



It is to be noted that in these three muscles there seems a regular 

 progression from above downwards. The latissimus dorsi is usually 

 served by a lower nerve than the teres, and this by a lower than the 

 subscapularis, and though they are occasionally equalised their posi- 

 tions in the series are never reversed. 



The circumflex nerve was shown in forty-three cases to be derived 

 from the 5th and 6th alone. It never received a fibre from the 7th. 

 In six cases, two of them adult, it came from the 5th alone, in 

 twenty-two from both 5th and 6th, and in the remainder it was un- 

 divided. It never arose from the 6th alone, and in many cases where 

 both nerves helped to form it the branch from the 6th was so small 

 that it could not be traced without breakage. I dissected the nerve 

 three times. In all these the teres minor was supplied by the 5th 

 only, and the deltoid by both 5th and 6th. The cutaneous branch 

 was in one from the 5th alone, in the other two received a fibre from 

 the 6th also. 



The musculo -spiral is formed sometimes by all four of the upper 

 roots, usually by the 6th, 7th, and 8th alone. Out of forty-six cases 

 the 5th and 6th were undivided in twelve, in nine of the remaining 

 thirty-four the 5th helped to form the nerve. Two of these were 

 adult. In twenty- five, fourteen of which were adult, it was 

 excluded. 



In one adult case where the 5th entered the nerve it was found by 

 dissection to run to the external cutaneous branch alone. 



The branch first given off is the nerve to the long head of the 

 triceps, with which sometimes goes the internal cutaneous branch. 

 The former was twelve times given from the 8th root, thrice from 

 both 7th and 8th, and once from the 7th alone, The internal 



