The muscles of the fore and hind limbs in Dasypus sexcinctus / by John Charles Galton.

  • Galton, John Charles.
Date:
[1868]
Catalogue details

Licence: Public Domain Mark

Credit: The muscles of the fore and hind limbs in Dasypus sexcinctus / by John Charles Galton. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    Deltoid.—This muscle appears to consist of three factors, which are as follow :— 1. Clavicular^ a flat muscular slip, arising from the acromial extremity of the clavicle. It has a rhomboidal (but almost approaching a triangular) shape, and narrows in breadth towards its insertion into a smooth oval facet situated on the outer aspeet of the deltoid trochanter of the humerus. This portion of the muscle, before its insertion, fuses with the rounded superior portion of the jpectoralis major, at the termination of this latter, and with the factor of the deltoid, next to be described. 2. Acromial, a stout, fleshy, suhcylindrical muscle, arising, slightly tendinous at origin, from the posterior half of the long acromial offset of the scapula, immediately in front of the “ metacromial process ” of Parker. It passes obliquely forward, and, after fusing with the clavicular factor of the deltoid, shares with it its insertion. 3. Scapular. This, the largest factor of the muscle, is triangular in shape, and arises from the whole length of the outer side of the principal (superior) spine of the scapula, from its termination at the base of the bone to its origin at the spring of the acromion ; being overlapped for the last inch and a half of its origin by the dorsal portion of the trapezius. It passes obliquely forwards, narrowing very rapidly from its broad base, to he inserted into the ridge bounding the facet which gave insertion to the two former factors of the muscle, hut becomes, moreover, eontinuous with the fascia of the arm, to which the occipital portion of the trapezius, as already described, furnishes a contribution. This factor of the deltoid overlaps that portion of the acromion which affords origin to the factor which I have termed acromial. Supraspinatus.—This muscle has no peculiarities worthy of record. It arises from the whole of the supraspinous fossa of the scapula, and has a very broad fleshy insertion into the upper edge of the external tuberosity of the humerus. Infraspinatus.—In the small infraspinous, or rather interspinous, fossa which lies between the greater and lesser spines of the scapula, arises the above muscle, which is inserted into the outer tuberosity of the humerus, at a point a little above that of the termination of the muscle next to he described. Teres minor.—A muscle of no great breadth, arising from the whole length of the lesser (inferior) spine of the seapula, above the origin of the “ long” head of the triceps. Passing forwards, parallel with the ridge from which it takes origin, it is inserted into a spinous projection below the outer tuberosity of the humerus, developed upon a ridge which runs upwards from the outer edge of the deltoid trochanter. Overlapping the origin of the “long” head of the triceps, and, close to its insertion, the origin of the external factor of the same muscle, it is overlapped in turn by the most posterior {sca- pular) portion of the deltoid. Subscapularis.—This muscle takes its ordinary origin from the inner aspeet of the scapula, and is inserted by a broad tendon into the inner tuberosity of the humerus. Teres major.—Arises from the posterior triangular space lying between the lesser (or inferior) spine of the scapula and the inferior angle of the bone\ At their origin, ' “ L’angle posterieur cles fatous est remarquable par sa courbure et sa saillie aigiie.” (Cuvier s Legons, 2nd ed. loc. cit. p. 352.)