30 
tuberosity, and separated by a considerable interval from the attach- 
ment of the infraspinatus to the dorsal face of the expanded radial 
tuberosity. Nevertheless there is no intervening structure between 
the two insertions, and the enormous lateral expansion of the neck of 
the humerus by means of the projections of the flattened tuberosities, 
in a plane almost at right angles to that of the projection of the 
epicondyles, may readily account for the dislocation of the insertion of 
a muscle which every other test would serve to indicate as teres minor. 
Amongst Edentata the muscle is generally, though not invariably, 
present. It is small in Chlamydophorus.* It is absent according to 
Macalister, at least as a muscle distinct from the infraspinatus, in 
both Bradypus didactylus and B. tridactylus and in Cyclothwrust, though 
Humphry?{ seems to have found it in the last two, taking for it a slip 
of the scapular deltoid arising from the scapular spine in Macalister’s 
viewt. 
Both in Chlamydophorus+ and Dasypus sexcinctus$ it arises from the 
‘‘ lesser’? or post-scapular spine of the scapula, the same which is pre- 
sent in Notoryctes (fig. 8, p.s.s.); and in Orycteropus capensis||, where the 
muscle is present, arising from the axillary costa, outer edge, there 
passes from the “middle of its inferior edge a strong tendon to the 
metacromial process of the scapula.” This would seem to represent 
the ligament which in Notoryctes extends from the post-scapular spine 
to the metacromion (fig. 8, p.s.m. lig.), bridging over the infraspinous 
fossa, but here no teres minor fibres arise from it. There can be little 
doubt that the second or post-scapular spine, when present, is to be 
regarded as an exaggeration of the dorsal lip of the “axillary” or 
posterior border of the scapula, from which in Orycteropus the teres 
minor arises. This lip in Chlamydophorus and Dasypus is fully de- 
veloped into a post-scapular spine, but still gives origin to the teres 
minor. The latter muscle in both cases overlaps the triceps, and I 
think it certain that the exaggerated development of the dorsal lip of 
the axillary border into a second spine is simply due to a great expan- 
sion of the great scapular head of the triceps. 
The muscle is absent in the Molef and in Gymnura,** but present in 
the Hedgehog, Cape Golden mole, and others.++ 
Amongst Rodents it is stated by Mivart and Murie{{ to be present in 
Agouti, and in Rabbit, Hare, and Guinea Pig, but itis closely adherent 
to the infraspinatus, with which these authors believe Meckel§$§ con- 
founded it when he failed to detect its presence in this order. 
Meckel§§ states that it is generally absent as an independent muscle 
in Carnivora; it is present, e.g., in Hyena striata, H. crocuta, and 
Viverra, according to Young and Robinson. |||| 
M. infraspinatus (fig. 8, 2.s.) arises from the deep and narrow 
postscapular fossa between the meso-scapular (fig. 8, m.s.s.) and 
post-scapular spines (p.s.s.). It is smaller than the supra- 
spinatus, and its fibres course outwards, and pass under cover of 
a narrow ligamentous bridge, which connects the post-scapular 
spine with the metacromion (fig. 8, p.s.m. lag.). It is then in- 
*xxvii., page 244. txxvii., page 245. {xxil., page 33. §xiv., page 
530. ||xv., page 574. ‘xi, page 214, **viii., page 395. tt xxvi., page 
795. ttxl., page 399. §§xxxvili., page 513. _ ||| Ixxil., page 190. 
