Marion Anne Jenkinson

“ It is hazardous to define individual variation (and also interspecific differences, as discussed later) in the origin of one vessel by relating its location to other vessels, because these may likewise vary in origin. But, by necessity, certain vessels that are probably less variable (axillary, carotid, and pectoral arteries) have been considered here as being constant in origin. If these three vessels are accepted as reference points, individual variants, as well as interspecific differences, can easily be described in the thoracic and coracoid arteries and in their various branches. ”

“ The vessel's homology with the internal mammary artery of mammals has been denied (Glenny, 1955:541) , and the name "mammary" is certainly not useful descriptively in birds. The term "intercostal" is less objectionable, except that such a name may call to mind segmental vessels arising from the dorsal aorta. The term "thoracic" seems best, as it is reasonably descriptive, and has been used by Glenny in the majority of his descriptions covering a wide variety of birds. The name "sternoclavicular" has been used by others as a synonym for the "coracoid" artery. ”

“ In both families the vessels that are relatively constant in appearance are: a subclavian giving rise to the carotid and axillary arteries, and becoming the pectoral trunk; the thoracic artery arising variously, and passing posteriorly to the rib cage; and the coracoid complex of vessels. The coracoid complex includes the coracoid artery, the vessels to Mm. sternocoracoideus and coracobrachialis posterior, and the sternal artery, which is variously present, and more extensive in some species than in others. ”