1898.] ANATOMT OF PBDETES CArFEB, 885 



(right) margin of the right precaval orifice. The musculi pectinati 

 converge to it. 



The Innominate artery divides at the right sterno-clavicular 

 articulation into carotid and subclavian ; the former runs along 

 the side of the trachea, and at the anterior border of the larynx 

 divides into external and internal carotids. 



The Subclavian artery gives off the vertebral just before the 

 vagus crosses it ; more externall}' it gives off a transversalis colli 

 to the side of the neck, and an internal mammary round which 

 the phrenic nerve loops as it does in man. 



The Axillary artery divides into two branches of nearly equal 

 size : one of these supphes the axilla, the other goes on as the 

 brachial ; the former divides into a ventral branch, which ac- 

 companies the internal anterior thoracic nerve to the pectorals 

 and panniculus, and a dorsal branch, which supplies the dorsal 

 part of the axilla, crosses dorsal to the brachial artery and nerves, 

 and passes through the quadrilateral space at the upper part of 

 the arm to join the circumflex nerve : it will thus be seen that 

 the termination of this artery corresponds to the posterior circum- 

 flex of human anatomy. 



The Bi-achial artery crosses ventral to the inner cord of the 

 plexus, and runs down the arm between the median and ulnar 

 nerves. About the middle of the arm it gives off a superior 

 profunda branch, which accompanies the musculo-spiral nerve to 

 the back. A little above the elbow an external branch is given off 

 which runs superficially to the skin of the outer side of the fore- 

 arm, while opposite the origin of this is an internal branch which 

 is probably the anastomotica magna. After this the brachial artery 

 passes through the fibrous supracondylar foramen with the median 

 nerve, and at the bend of the elbow gives off a small ulnar branch, 

 which, however, ends in the muscles of the forearm. The main 

 artery now divides into a common interosseous, supplying the 

 deep parts of the front and back of the forearm, and the median 

 artery, which accompanies the nerve of the same name into the 

 hand. 



The Thoracic and Abdominal Aortce give off the same branches 

 as in the Eabbit. The aorta bifurcates opposite the 6th lumbar 

 vertebra, the caudal artery being given off from the dorsal surface 

 of it, about I inch before the bifurcation. The Common Iliac 

 arteries bifurcate into external and internal iliacs, close to the 

 inner border of the tendon of the psoas parvus. 



The Internal Iliac runs backv^ard along the dorsum of the 

 pelvis for some little distance ; it then gives off a vesico-haemor- 

 rhoidal branch, which divides to supply the bladdei*, uterus, and 

 rectum, and a gluteal branch, which escapes from the pelvis 

 through the great sciatic notch. The point where the gluteal 

 branch comes off I regard as the division between the anterior and 

 posterior, or rather ventral and dorsal, trunks of the internal iliac 

 (see " 6th Collective Investigation Beport of the Anatomical Society 

 of Gt. Britain and Ireland," Journal of Anatomy, vol. xxx. p. 31). 



