2 PROFESSOR OWEN ON THE OSTEOLOGY OF 



about one-third of the length of the scapula from the lower angle to define tlie rough 

 tract (m) for the attachment of the teres major. 



The upper border is moderately concave, and in old Gorillas is divided by a growth 

 of bone («) in the outer root of the transverse ligament bridging over the super- 

 scapular nerve and vessels as they traverse the superscapular notch, which is wide and 

 shallow. The basal border (o, «) describes two convex curves, with an opposite one 

 at the origin of the spine (s) : it is thicker at the lower half of both the convex curves 

 than at the upper half, but is nowhere so thin as is the upper border. The lower 

 border ((/, m) is almost straight : it forms a rough ridge an inch in length below the 

 glenoid cavity (g) for the origin of the long head of the triceps muscle ; beyond this 

 extends the ridge, forming the lower part of the convex boundary of the subspinal tract, 

 straight to the origin of the teres major, where the ridged border forms a slight convexity 

 in the old Gorilla. 



On the inner surface of the scapula, the deepest part of the concavity runs parallel 

 with the attachment of the spine on the opposite surface : the origin of the subscapularis 

 is bounded above near the upper and outer angle by a ridge dividing that muscle from the 

 serratus magnus, which has a nearly flat triangular space at that angle of I he scapula for 

 its upper origin. Tlie subscapular fossa is subdivided by six ridges of various lengths, 

 having a direction converging towards the neck of the bone : the fourth and sixth ridges 

 are the longest ; the latter divides the subscapularis surface from the longitudinal channel 

 bounded by the ridge for the teres minor, which forms the lower border of the bone. 



The glenoid articular cavity (fig. 3), like that in Man (fig. 8), is of an oval or pyriform 

 shape with the great end downwards ; the inner margin is thicker than in Man, and like 

 the outer one, shows concentric lines for the attachment of a strong capsular ligament — 

 except at the upper and outer part, which is smoothly convex and broader than other 

 parts of the margin. The spine of the scapula progressively rises, or augments in depth, 

 as it approaches the base of the acromion ; its sides are concave and thin between the 

 supra- and infra-spinal muscles ; the margin is rough, and increases in thickness as it 

 approaches the great acromial expansion. The base of this process, rising clear of the 

 blade-bone an inch or more from the glenoid cavity, curves outward, forward, and 

 slightly upward, with a kind of twist as it expands into the broad rough acromion. This 

 is convex and rough above, concave and smooth where it arches over the head of the 

 humerus. The upper border is undulating but chiefly concave, and affords, near the 

 apex, the articular surface for the clavicle ; the opposite border is convex, with a well- 

 marked protuberance, strengthening the origin of the deltoid. The extent of rugged sur- 

 face afforded to this powerful muscle is very great. The coracoid process (c, figs. 1,2,3) 

 arises by a thick basis from nearly two inches of the upper part of the scapula next the 

 glenoid cavity : it is twisted inwards and forwards, and expands into a rhomboidal plate, 

 almost flat on its outer surface (fig. 2). The upper border presents a convex prominence 

 at its distal half for the attachment of the triceps ; the lower border is thicker, with a 



