PLATE V. 



THE INNER VIEW OF ARM AND BRACHIAL ARTERY. 



The cutaneous nerves of the front of the arm are (a) circum- 

 flex ; (b) intercosto- humeral, just along the anterior fold of the 

 axilla; (c) tin- internal cutaneous, a branch of which pierces the 

 fascia above the main nerve ; (el) the upper external cutaneous 

 branch of the nuisculo-spiral ; (e) the lesser internal cutaneous; 

 (/) the external cutaneous. 



The inferior prnfuntla artery is occasionally absent, and is also 

 very variable in si/c and origin, and may arise in conjunction with 

 the superior profunda, then running down with the ulnar nerve. 

 In thu plate it is shown arising by two trunks, one which has been 

 called the inferior profunda (/) (firstly because it arises from 

 about the normal place of origin, and secondly because it pierces 

 the internal intermuscular septum), the other which is called an 

 accessory branch (e), and arises from the superior profunda. 



Another branch of the brachial, the vas aberrant, ' usually 

 present, but often as a minute vessel, not admitting complete 



in, arises close to or with the superior profunda, and descends over the median 

 nerve supplying the biceps. Its downward continuation, when present, joins either the 

 radial artery, or more rarely the ulnar, and may be minute, moderate or large enough to 

 replace, or simulate the brachial, which then appears to overlie the median nerve. When 

 of moderate size, it may replace the brachial origin of the radial (rarely the ulnar), giving 

 rise to the common condition called high bifurcation of the brachial.' (Macalister.) 



Note on the Coraco-brachialis. Professor Wood ' has shown that in mammals this 

 inn -de consists of three portions : 1. The coraco-brachialis brevis, represented in man by 

 a fibrous arch, rarely by muscle, arising from the coracoid process and inserted into the 

 humerus just below the subscanularis. 2. The coraco-brachialis iai-<li;is, or the coraco- 

 brachialis of man. 3. The coraco-brachialis longus arises with the medius, being 

 connected at its nrii'iii with the pectoralis minor, and passes down internal to it to join 

 tlie internal int. nnir-rnlur septum, in which it is usually traceable as far as the internal 

 ('iiulyle. It is usually represented in man by a fibrous band passing from the lower 

 part of the muscle to the intermuscular septum. The coraco-brachial apparatus is 

 found liest developed in those animals 'which use the fore limbs for prehension, 

 climbing, swimming, 'lining, etc., and appears to refer more to the wants and habits, 

 than the pedigree or relationship of the animal.' The musculo-cutaneous nerve may 

 either pierce the medius, or more usually it passes between the medius and longua. 



1 fount, of Anal, and 1'liyi. vol. i. 



