27 
scapula in its whole extent, and from the septum between it and 
the adjacent teres major, and they are inserted into the lesser 
(postaxial) tuberosity of the proximal end of the humerus. 
The muscle not only covers the mesial aspect of the compara- 
tively narrow scapula, but projects both anteriorly and posteriorly 
beyond the limits of the bone so as to lie in contact with the 
supra-spinatus preaxially and with the broad scapular head of the 
triceps postaxially (the latter muscle being attached to the whole 
of the postaxial or “axillary” border of the scapula). 
Neither in Marsupials nor in the Eutherian orders with which com- 
parison has been specially made does the subscapularis present features 
which call for special remark. It varies for the most part merely in 
its size relative to other muscles and to its surface origin, and in its 
degree of attachment to or freedom from the teres major on the one 
side and the supra-spinatus on the other. In the Dog Humphry* notes 
that it is partly blended with the supra-spinatus, and in the Mole with 
the teres major. Freeman,+ however, describes it as a small indepen- 
dent muscle in the last-named form. 
In Ornithorhynchus Owen notes it as a very narrow muscle. I find 
it relatively rather broad, much exceeding the width of the scapular 
plate, occupying indeed portions of both inner and outer surfaces. In 
a recent short paper$ Dr. W. J. 8. McKay and the writer have called 
attention to the significance of this attachment of the subscapularis in 
the identification of the borders and surfaces of the monotreme scapula. 
In Hchidna, subscapularis, according to Mivart and Westling,|| is 
confined to the outer surface of the scapula posterior to the origin of 
the long head of the triceps. 
Dr. McKay and the writer find that in Echidna the muscle arises 
largely as Mivart describes it, but that in addition it arises from the 
whole of the actual posterior border of the scapula, and slightly en- 
croaches upon the inner aspect of the bone, when its limit is indicated 
by a faint ridge near the margin. 
The muscle which Leche? takes for subscapularis in Ornithorhynchus 
is certainly not the homologue of the true subscapularis, which he 
rightly recognises in Hchidna, but corresponds to that which Westling 
names the subscapularis accessorius in Echidna. The true subscapularis 
in Ornithorhynchus is erroneously described by Leche as a large second 
part of teres major (q.v.). 
M. teres major (figs. 6 and 7, tm.) arises from the posterior 
(post-scapular) angle of the scapula, which forms a backwardly 
prolonged horn of the crescentic base or mesial border of the 
bone (vide fig. 8), and from a tendinous intersection between it 
and the adjacent axillary. border of the M. subscapularis. 
Its origin from bone is narrow and tendinous, and from it the 
muscle spreads out somewhat in its course towards the proximal 
part of the shaft of the humerus, into which it is inserted, under 
*xx., page 158, Note. txi., page 214. {xlv., Vol. iii, page 5. § Ixiv. 
XXx1x., page 384. {/ xxvi., page 796. 
