PRIMROSE : THE ANATOMY OF THE ORANG OUTANG 
29 
from the tendon of the pectoralis minor. Wood^ has described in man 
a case in which the muscle joined the coraco-acromial ligament and 
another in which it was inserted into the clavicle and the costo-coracoid 
membrane. 
The Serratus magnus arose from the upper eleven ribs, interdigitating 
below with the external oblique muscle of the abdomen and was 
inserted into the whole length of the vertebral border of the scapula, 
blending above with the levator anguli scapulae at its insertion. Pick 
describes an origin in the Orang from twelve ribs. In man the muscle 
rarely extends beyond an attachment to the upper nine ribs. 
The Deltoid arose from the outer third of the anterior surface of the 
clavicle, from the acromion process and from the spine of the scapula 
also from the fascia over the infra-spinatus muscle. It was inserted 
into the outer aspect of the humerus as in man; some additional slips 
pass to the humerus for about 2 cm. above the main point of insertion, 
and some superficial fibres pass to the fascia, which extends down to the 
external condyle. Pick speaks of this muscle as similarly well 
developed in his Orang. 
The Teres major arose from the lower fourth of the axillary border of 
the scapula and from the dorsal surface of the inferior angle; its insertion 
3cm. wide found attachment to the humerus behind the latissimus 
dorsi. The lower part of the muscle near its insertion was joined by 
the slip from the latissimus dorsi already described (p. 21). 
The Teres minor^ the Supra-spinatus and the Infra-spinatus muscles 
had similar attachments to those found in man; it was noted, however, 
that the aponeuroses of insertion of the last two muscles were directly 
continuous with one another and blended with the capsule of the 
shoulder joint. 
The Subscapularis resembled that found in man. Pick described a 
slip of origin of this muscle from the teres major. 
The Subclavius was not strongly developed, measuring only 0.3 cm. 
in width; it arose from the cartilage of the first rib, and had an insertion 
2 cm. wide into the clavicle at the junction of the middle and the outer 
thirds of that bone on its under aspect; it here extended to the point of 
attachment of the coraco-clavicular ligament, but was in no manner 
continuous with that structure. The subclavius is poorly developed in 
I J. Wood, “Variations in Human Myologj'.’’ Proceedings of the Royal Society of London, Vol. 
XV, 1867, p. 231. 
