MUSCULAR SYSTEM. K^3 



the ischium ; posteriorly, to the transverse processes of the four or 

 tive uppermost bones of the coccyx. 



Action. — To assist in the depression of the tail; but, princi- 

 pally, to maintain it forcibly compressed against the rump. 



MUSCLES OF THE EXTREMITIES. 



Of the three hundred and odd muscles reckoned in the whole 

 body, upwards of one hundred are to be found in the four ex- 

 tremities. 



MUSCLES OF THE FORE EXTREMITIES. 



In number, forty-eight ; and they admit of being classed into 

 two general divisions — those of the shoulder, and those belong- 

 ing to the arm and leg. Both divisions are, more or less, in- 

 vested by the scapular and humeral portions of muscles coming 

 from the trunk ; most of which give origin to aponeurotic expan- 

 sions that descend and subsequently form the humeral and bra- 

 ch\?dfaschi(E. Upon the outer and posterior sides we find the 

 panniculus ; upon the fore parts, the levator humeri, pectoralis 

 parvus et magnus ; upon the hind and inner parts, the pectoralis 

 transversus ; upon the internal side, the latissimus dorsi. Upon 

 the shoulder the faschia is thin, weak, and transparent; and 

 has (besides its connexions with the various muscles mentioned) 

 attachments to the superior costa and spine of the scapula, to the 

 tubercles and projections of the humerus, and to the olecranon. 



MUSCLES OF THE SHOULDER 

 Are twelve in number. 



1.— EXTERNAL SCAPULAR REGION 

 Comprehends two muscles occupying the (^ors2/msca/)M/«. These 

 are enveloped in distinct portions of dense faschia, from which 

 septa are sent down between them, and to the inner surfaces of 

 which, in many places, the fleshy fibres are inseparably ad- 

 herent. 



ANTEA-SPiN ATUS, — Super-acromio trochiterius. 



Situation. — Occupying the fossa anfea spinata scapula. 



Figure. — Approaching that of an extended triangle ; having its 

 base thick and turned downwards, its apex thin and rounded 

 ofF. 



Attachment. — Superiorly, to the surface of the fossa antea 

 spinata; also to the spine and anterior costa of the scapula : in- 

 feriorly, to the summits of the greater and lesser tubercles of the 

 humerus, and to the capsular ligament of the shoulder joint. 



