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for or serve to push along the rapidly-moving body. Stronger fixation is therefore a greater necessity posteriorly than anteriorly. In any case, whatever the explanation, this important difference exists.

Fig. 25.—Right scapula of Dog (Canis familiaris). × ¼. a, Acromion; af, prescapular fossa; c, coracoid; cb, coracoid or anterior border; css, indicates the position of the coraco-scapular suture, obliterated in adult animals by the complete ankylosis of the two bones; gb, glenoid or posterior border; gc, glenoid cavity; pf, postscapular fossa; s, spine; ss, suprascapular border. (From Flower's Osteology.)


Fig. 26.—Right scapula of Red Deer (Cervus elaphus). × ¼. a, Acromion; af, anterior or prescapular fossa; c, coracoid; gc, glenoid cavity; pf, postscapular fossa; ss, partially ossified suprascapular border. (From Flower's Osteology.)

The shoulder-blade of mammals is as a rule a much-flattened bone with a ridge on the outer surface known as the spine; this ridge ends in a freely-projecting process, the acromion, from which a branch often arises known as the metacromion. This gives a bifurcate appearance to the end of the ridge. The spine is less developed and the scapula is narrower in such animals as the Dog and the Deer which simply run, and whose fore-limbs therefore are not endowed with the complexity of movement seen, for instance, in the Apes.

It has been pointed out that the area which lies in front of