56 PROCEEDINGS OF THE ANATOMICAL AND ANTHROPOLOGICAL 

 RECORD OF ANATOMICAL VARIATIONS. 



Date of observation, May, 1905. 

 Sex, Female. 



Branch from the nerve to the subclavius entering the thorax (left). 

 A small nerve came off the upper trunk of the brachial plexus, 

 just as this trunk emerged from beneath the scalenus anticus muscle. 

 It then passed downwards over the other trunks of the plexus, to 

 where the subclavian artery is crossed by the external jugular vein. 

 Here it lay between this vein and the artery. It then hooked round 

 in front of the external jugular vein, and, running down and in, 

 crossed the subclavian vein, just before this vein joined the internal 

 jugular. It then entered the thorax, lying between the internal 

 mammary artery and the left innominate vein. Its termination could 

 not be followed. As it crossed the external jugular vein, it gave off 

 a muscular branch to the subclavius. 



(Signature of observer) DAVID S. GARDEN. 



Date of observation, May, 1905. 

 Sex, Male. 



Abnormalities in the branches of the arch of the aorta. 

 There is no innominate artery. The right subclavian artery arises 

 separately as the last branch from the arch. The two common carotids 

 arise by a short common trunk, and the left vertebral arises from the 

 arch of the aorta, instead of from the subclavian. 



The arrangement of these branches is as follows : 

 The first branch arises from the upper and front part of the arch 

 in front of the trachea. It is about ^ inch long, dividing almost im- 

 mediately into right and left common carotids. Close to the left of 

 this a branch arises slightly smaller than the left common carotid, 

 parallel to which it runs up into the neck. This is the left vertebral. 

 To the left of this arises the left subclavian. Lastly a large branch 

 the right subclavian arises from the upper and back part of the arch 



