62 PROCEEDINGS OF THE ANATOMICAL AND ANTHROPOLOGICAL 



Date of observation, 4th May, 1911. 

 Sex of subject, Female. 



Rectus Sternalis. 



The rectus sternalis is a long, thin, narrow muscle, situated at the upper 

 and fore part of the chest. It arises from the anterior surface of the first 

 piece of the sternum. The left rectus sternalis arises from the base of the 

 sternal origin of the right sterno-mastoid, and its fibres run downwards and to 

 the left. The muscle at its origin consists of aponeurotic fibres which interlace 

 with those of the corresponding muscle of the right side. As the muscle 

 descends the fibres become fleshy and the muscle itself narrower and more 

 rounded. It is inserted by a tendon into the upper border of the cartilage of 

 the fifth rib about H inches from the mid-sternal line. 



In the third intercostal space a nerve and an artery pierce the fibres of 

 tho pectoralis major, and enter the deep surface of the rectus sternalis. These 

 are branches from the intercostal artery and nerve. In the second intercostal 

 space a nerve and an artery pierce the pectoralis major on the inner side of 

 the rectus sternalis, but instead of entering that muscle cross in front of it. 



This muscle, during the whole of its course, lies superficial to and free 

 from the pectoralis major, and has a separate sheath of its own. The muscle 

 of the left side is smaller than and not so well developed as that of the 



right side. 



(Signature of observer) ROBERT FORGAN. 



Date of observation, 7th May, 1911. 

 Sex of subject, Female. 



A Third Head to the Biceps Muscle. 



It is about a quarter of an inch broad, and arising above at the upper 

 and outer part of the brachialis anticus is inserted into the bicipital fascia 

 and inner side of the tendon of the biceps below. It lies on the outer side 

 of the brachial artery above and above it below. 



The musculo-cutaneous nerve does not in this case pierce the coraco- 

 brachialis. The brandies to the biceps and brachialis anticus are given off 

 below the insertion of the coraco-brachialis. 



(Signature of observer) F. NORRIE. 



