148 couES, 



ulna itself, at, about the middle of the bone. The slip is of a nearly- 

 uniform width of about a third of an inch, and is thin and flat ; it has 

 the usual action. 



(b'. — From scapular arch ; "long.") 



Biceps. — The coraco-radial flexor is in two parts, with rather unu- 

 sual disposition; one of the " heads " is much larger than the other, 

 and the two arise far apart ; but they are implanted together upon the 

 radius. The anterior part — epicoraco-radialis — arises fleshy high up 

 on the epicoracoid plate from its border and postero-interior moiety, 

 where it is overlaid by the episternum, and soon forms a slender 

 terete fascicle, which passes outward in relation with the origin of 

 the rectus abdominis, subsequently overlies the anterior portion of 

 the coraco-brachialis, and then comes in relation of contiguity with 

 the other moiety of the biceps, which it separates from the pectoral 

 crista humeri. Passing this last, it changes to a long terete tendon 

 that represents the anterior border of the biceps where this dips be- 

 twixt the forearm muscles. The posterior and larger part — coraco- 

 radialis — arises from the sternal extremity of the coracoid in com- 

 mon with one head of the coraco-brachialis, and immediately swells 

 into a great, broad, flattish, fleshy belly that passes down the arm lying 

 a little obliquely upon both the coraco-brachiales, and subsequently 

 upon the tendon of the latissimus dorsi. It becomes penniform by in- 

 sertion into the tendon of the other head of the biceps ; posteriorly, 

 the muscular fibres nearly reach the radius. The common insertion 

 of the two is by a broad flat tendon into the middle third of the 

 radius. 



(The other (ulnar) flexor cubiti is noticed under the next head, c'). 



Triceps, its long head. Bectiis humeri ! — The "long" or scapulo-ulnar 

 extensor of the forearm is remarkably distinct from the two humeral, 

 or " short " heads. It arises fleshy from the posterior concave bor- 

 der of the scapula, from the glenoid an inch or so backward. It is 

 thus a rather thin broad plane, that passes between and separates the 

 two teretes majores (see above) from the other scapulo-humeral mus- 

 cles ; as it descends the back of the arm, it narrows in one transverse 

 direction, and thickens in the other, so that here its greatest diameter 

 is at right angles with the same diameter above. The anterior 

 (glenoid) edge of the muscle is at first in apposition with the poste- 

 I'ior surface of the brachialis internus; after the above mentioned 

 change in the long diameter of the muscle, its broad flat surface is 

 similarly applied to the equally expanded surface of the brachialis 

 internus. In place of ,the tendinous inscriptions that commonly 

 unite this scapular head below with both the humeral heads, we have 

 them separated by cellular intervals. Neither is there an aponeurotic 

 investment of the muscle below; but it has a wholly fleshy, thin, 



