112 MUSCULAR SYSTEM. 



investing them ; infeiioiiy, to a small tubercle upon the spine of 

 the scapula. 



Relations. — Superiorly, it covers the rhomboideus brevis ; in 

 its course, downward, it passes over the posterior costa of the 

 scapula; and also the postero-superior angle of the latissimus 

 dorsi : inferiorly, it lies upon the aponeurosis enveloping the 

 dorsum scapulae. 



Direction. — Perpendicular; excepting the posterior fasciculi, 

 and they slant forward, in their course downward. 



Structure. — Superior attachments, aponeurotic; below, it ends 

 in a flat triangular tendon ; the intermediate parts are entirely 

 fleshy. 



Action. — To elevate the scapula : and, when the posterior 

 fasciculi prevail, to incline the bone at the same time, backwards. 



LATISSIMUS DO RSI. — Dorso-humeralis. 



Situation. — Upon the supero- lateral part of the chest, behind 

 the scapula. 



For^n. — Flat, thick : an extended triangle, presenting its base 

 towards the spine. 



Attachment. — Superiorly, to the spinous processes of the dor- 

 sal vertebrse, and to the ligamentum colli (vel potius, dorsi) 

 investing them ; stretching as far forwards as the highest point 

 in the withers, and as far backwards as the lumbar spines, to 

 some of which it is also connected : inferiorly, to the inner and 

 upper part of the body of the humerus. 



Relations. — Superiorly, with the trapezius, rhomboideus bre- 

 vis, and posterior angle of the scapula ; inferiorly, with the triceps 

 extensor brachii : externally, with the panniculus ; internally, 

 with the ribs and serratus magnus. 



Direction. — Oblique: downwards and forwards; the fibres 

 converging in their course. 



Structure. — Superior part, a broad and extended aponeurosis ; 

 inferiorly, it ends in a long, flattened, thin tendon : the interme- 

 diate parts are entirely flesliy. 



Action. — To flex the humerus, by drawing it backwards and 

 elevating its inferior extremity. 



RHOMBOIDEUS BREv IS. — Dorsosubscopularis. 



Situation. — Upon the side of the withers: deeply seated. 



Form. — Flat and square. Thin, superiorly; thick, inferiorly. 



Attachment.— Superiorly, to the four or five anterior dorsal 

 spinous processes, and to the ligament clothing their summits : 

 inferiorly, to the inner part of the superior costa of the scapula, 

 and of the cartilage surmounting it. 



