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Show 194 MR. A. H. GARROD ON THE [Feb. I, remiges at the elbow. Its remarkably long and slender tendon, which frequently traverses a fibrous pulley on the axillary margin of the teres muscle, runs up the arm side by side with the axillary vessels and nerves to be inserted in the thorax, into the middle of a tendon which runs from the inner side of the middle of the scapular element of the scapulo-coracoid articulation to near the middle of the thoracic border of the sterno-coracoid articulation, at right angles to it when the fore limb is extended. This arrangement being found very well differentiated in the Storks, may, for the sake of convenience, be termed Ciconine. In Chauna it is exactly the same, as may be seen from the accompanying drawing (Plate XIV. fig. 1, e.s). In the majority of the Gallinaceous birds the expansor secundariorum, with the normal origin from the secondary quills, has a different method of insertion, which has led M . A. Milne-Edwards to describe the muscle in the common Fowl as a part of the coracobrachialis (brevis) in his superb work on fossil birds. In the genera Tetrao, Francolinus, Rollulus, Phasianus, Euplocamus, Gallus, Ceriornis, and Pavo, the muscle instead of being inserted into the scapulo-sternal fibrous band above referred to, after blending to a certain extent with the axillary margin of the teres, ceases by becoming fixed to a fibrous intersection about one third down the coraco-brachialis brevis muscle. In Francolinus clappertoni from among the Francolins, Coturnix, Odontophorus, Ortyx, Eupsyckortyx, and Numida, the tendon does not go so far as the short coraco-brachialis, but ends either by simply joining the axillary margin of the teres, or by at the same time sending a tendinous slip behind it to the scapula. In Argus giganteus the tendon, running from the elbow, turns round the axillary border of the teres to end by joining a triangular muscular fasciculus, attached by its base to the upper portion of the thoracic surface, which appears to be nothing but a differentiation-off of the upper portion of the last-named muscle. In the Cracida this insertion into the scapula is also found, but it is tendinous, like the upper element of the thoracic band above described in the Storks and Chauna; and iu them there is also a second tendinous slip from the axillary margin of the coraco-brachialis longus (Plate XII. fig. 5) (not the brevis). In the Megapodidae also the attachment to the coraco-brachialis brevis is wanting, the tendon ending either by blending with the teres-margiu, or running on to the scapula. In the Ducks and Geese among the Anseres the tendons under consideration, when they enter the thorax, run towards one another and join, after having expanded out, in the middle line, in front of the oesophagus, .and behind the trachea. In the Swans this arrangement is not' found, the tendons ending in the ciconine manner, or by running to the upper end of the scapula ; and in this respect Sarcidiornis resembles them. From the tabular statement now exhibited (see p. 199) the nature as well as the presence or absence of this muscle can be determined in any special group of birds. The only Anomalognathous birds in which I have found this muscle are the Coraciidae. |