FELIS SPEL^A. 115 



scapularis muscle. Externally it is bounded by the greater tuberosity {b), a massive 

 ridge much more elevated than in the Bear, but less so than in the Hyaena. To the 

 external edge of the latter were attached the tendons of the supra- and infra-spinatus 

 muscles, to the internal and anterior edge the tendon of the muscle called by Strauss- 

 Durkheim the sterno-trochiterian,^ vs^hich represents a portion of the pectoralis major in 

 man, though it differs considerably from that muscle in position and office. To the 

 posterior portion of the same tuberosity was attached the small rotundus minor, that 

 along with the infra-spinatus acts as the rotator of the limb in an outward direction. 

 Immediately within the free edge of the tuberosity is a supplementary process directed 

 inwards, with its greatest diameter downwards forming the outer edge of the bicipital 

 groove, which is deep and large, and bounded on the inner side by the projecting ante- 

 rior portion of the lesser tuberosity. These edges are joined in the living animal 

 by a very strong ligament, forming a closed canal furnished with a synovial membrane, 

 through which plays the upper tendon of the single muscle analogous to the biceps of 

 human anatomy. 



A sharp ridge {h) bounds the lesser tuberosity inferiorly and posteriorly, and 

 forms the internal edge of the posterior proximal surface of the bone. A rounded ridge 

 descends from the articulation on the outer side of the same surface, forming, together 

 with h, a broad and deep depression, into which is inserted the first head of the anconeus 

 raedius of Strauss-Durkheim, a muscle which has no analogue in man, but which in Felis 

 aids the triceps medius in the extension of the fore-arm. The flat internal sm*face on the 

 upper half of the shaft affords a broad attachment for the aponeurosis of the two branches 

 of the latissimus dorsi, between them for the teres muscle, and above the latter for 

 the coraco-brachial muscle. The deltoid space is a large triangular roughened surface on 

 the convex outer portion of the bone, the base being formed by the greater tuberosity, and 

 the apex situated at a distance from the proximal end of rather more than two fifths of 

 the entire length of the bone, being the result of the union of the anterior and posterior 

 deltoid ridges. Of these the former is the proximo-anterior edge of the bone, and affords 

 attachment to the pectoralis major ; the latter, situated on the antero-external surface at a 

 lower level, afford insertion to the brachialis muscle. These ridges after their fusion pass 

 downwards for a short distance, and turning outwards gradually die away on the 

 external surface of the bone. To the upper and posterior portion of the deltoid space is 

 attached the delto-spinal, to the anterior and lower the delto-acromial muscles. Immedi- 

 ately behind the proximal end of the posterior deltoid ridge there is a slightly roughened 

 surface, which affords attachment to the head of the triceps externus. The proximal 

 portion of the Feline humerus may be differentiated from that of the Bear by the presence 

 of the following characters in the latter animal : — The deltoid space is much larger, the 

 ridges much more strongly developed, the tuberosity is smaller, and the shaft is not so 



1 'Anat. du Chat,' vol. ii, p. 337. He terms the greater tuberosity the trochiter and the lesser the 

 trochin. 



