ANATOMICAL SOCIETY OF GREAT BRITAIN AND IRELAND. Iv 



remembering, however, that on this side the first and second ribs are 

 not fused, and that the branch running to the back of the neck, which 

 corresponds to the arteria profunda cervicis, passes up in front of 

 the neck of the first, and not through two fused ribs. 



From a consideration of the arrangement of the arteries in this- 



Fig. 2. — A, left superior vena cava; B, ductus arteriosus; C, constriction in 

 descending aorta ; D, branch passing from aorta to subclavian ; E, vena 

 azygos major transposed ; F, vena azygos minor superior ; G, vena azygos 

 minor inferior ; H, arteria profunda cervicis passing up through I which 

 represents the 1st and 2nd ribs ; K, connecting portion of kidneys : I, in- 

 ferior mesenteric artery ; N, pelvis of kidney ; P, branch to right kidney 

 from right common iliac. 



region, it seems probable that this large vessel, passing between the 

 subclavian and the descending thoracic aorta, is a reinforcing branch 

 to the latter, produced by an enlargement of the anastomosis between 



