72 THE STRUCTURE OF MAN 
muscles, but its original independence and greater significance is 
seen in the fact that it ossifies from two distinct centres, which 
in Man only completely fuse with one another and with the 
bony scapula after the sixteenth to the eighteenth year. [This 
double ossification of the coracoid occurs only in Mammals 
among living Vertebrates. The overhanging portion of the 
coracoidal region of the human blade-bone, which (co., Fig. 
52) from its suggestiveness of a bird’s head has been termed 
the “coracoid process,” answers in 
every detail of relationship to the 
epicoracoid of the lowest Mammals 
(e.c., Fig. 28). The basal portion, or 
second coracoidal element (which 
does not appear in the human sub- 
. ject until the fourteenth or fifteenth 
year), represents, in a highly reduced 
and vestigial condition, the more 
robust element of the Ornithorhyn- 
chus coracoid (m.c., Fig. 28). It was 
Fic, 52.—Rrant Brape-Bowr or « Until recently known as the “ coraz 
NEW-BORN CHILD, SEEN FRoM THE CO1d”; but, as it and the epicoracoid 
paar nar aia een together represent the entire coracoid 
co., coracoid process ; the dark spot 
at os. represents the first of its two of the lower Vertebrata, the term 
pane of OSU NOLS Gi, articular metacoracoid is now applied to it.] 1 
acet for humerus ; sc., scapula. 
The scapula is in Man a broad 
bone, its form being doubtless attained in functional adaptation to 
a very strongly developed shoulder musculature. In those lower 
animals, in which the anterior limbs are simple ambulatory organs 
performing less complicated movements, the scapula is not so broad, 
especially at its median and hinder border—the so-called base. It 
is therefore very interesting to be able to prove, both by the 
Anatomy of the lower races (Negroes and aborigines of Australia) 
and by human Ontogeny, that the great breadth of the median 
part of the human scapula, and the sharper differentiation of its 
spine, may both be considered as secondarily acquired features, 
which stand in direct relation to the gradually increasing func- 
tional activity of the fore-limb.? 
1 (Cf. Lyndekker and Howes, Proc. Zool. Soc., Lond. 1893, pp. 172 and 585.] 
2 [The scapula of the higher Mammalia differs most conspicuously from that of 
the lowest Mammals and all lower Vertebrates, in its expansion, cephalad of its spine, 
to form the so-called prescapular lamina. This is but feebly formed in Man. It 
attains its highest development in association with marked specialisation of the 
fore-limb—not, however, always for the same purpose. This is readily seen, for 
