BY W. J. S. McKAY. 279 



major, while its outer margin is contiguous with the anterior 

 border of tlie dermo-flexor brachialis." 



CouES says, " The pectoral major is of remarkable extent. Its 

 origin is in a line from the acromion and whole episternal bar, 

 and thence down the manubrium and sternum and linea alba to 

 within a couple of inches of the pubes. Along the chest it has 

 thick fleshy origin from the ends of the ribs as well as from the 

 breast lione. The abdominal portion is extremely thin — thinner 

 than the same part of the panniculus ; the muscle thickens rather 

 abruptly as it passes over the lower edge of the thorax, and there, 

 near the median line, a slight cellular interval may occur between 

 thoracic and abdominal portions. The chest portion is of nearly 

 uniform and great thickness ; there is no evident distinction of a 

 deep-seated from a superficial part ; but the outer half of the 

 episternal portion and the acromial portion are together separable 

 from the sternal portion by a slight cellular interval along a line 

 representing the posterior border of the muscle below described as 

 anterior part of the deltoid [epicoraco.-humeral]." In a note on 

 this last sentence, Coues says, " These portions together are in the 

 ordinary position, and have much the appearance of a deltoid ; in 

 fact they resemble one much more than the muscle below described 

 as anterior-deltoid [epicoraco-humeral], does." 



Meckel says — " Ex artus anterioris musculis P. major, revera 

 maxinms, praecipue longissimus est, triangularis, a clavicula 

 acroiuiali et prirai ossis sternalis ramo transverso fere ad symphysin 

 ossium pubis extensus, fere totam thoracis abdominisque longitu- 

 dinem explet. Margine interno cum opposito confluit, prseterea 

 dimidio anteriore, minore a costarum sternalium anteriorum sex 

 fine interno ortus, angulo superiore et externo toti ossis brachii 

 spinae anticse inseritur tendine lato et brevi, hie simul cum 

 musculo cutaneo unitus. 



CuviKR and Laurillard figure the pectoralis on Plate 267 as, 

 I, grand pectoral jjortio sternale (sterno-humerien), which includes 

 our clavicular deltoid; and I'idem portio costaie et meme ventrale, 

 the latter being the P. quartus as described above. (For remarks 

 on the pectoral muscles vide M. deltoideus.) 



