body when the animal is climbing. Corresponding modifications will be found in the posterior extremities.
The Teres Major was proportionately a stronger muscle than in man, and its tendon was inserted over a space of one inch and three-eighths: this was partly caused by its receiving a slip, as before mentioned, from the Latissimus Dorsi.
The Teres Minor differed only in its mode of origin; arising between the long head of the Triceps and the Infra-Spinatus muscles from the inferior border of the scapula.
The acromial portion of the Deltoid was inserted separately into the humerus by a thin tendinous band, while the mass of the muscle was inserted into the deltoid tuberosity, which was situated lower down the arm than in man.
In the Magot, it was divided, as stated by Duvernoy, into three almost distinct portions, which he calls Claviculaire, Coracodienne, et Sous-epineuse.
The Pectoralis Major arose by three distinct heads; one coming from the clavicle, the other two from the sternum and intercostal cartilages. The upper sternal portion did not, in this instance, reach higher than the third rib. The lower sternal portion arose from the costal cartilages, the ensiform appendage, and the sternum: it received, opposite the fifth rib, some fibres from the external oblique. The muscle was inserted by a broad tendon, extending from the anatomical neck, 218 inches down the anterior border of that bone. The fibres of the clavicular portion form the lowest and those of the lower sternal portion, the upper part of the tendon, as in man.
In the Chimpanzee (Vrolik, l.c. p. 18), this muscle has only a single sternal and clavicular origin. And Prof. Owen[1] describes it as formed in the Orang of sterno-humeralis, costo-humeralis, and sterno-costo-humeralis portions—apparently, therefore, in his specimen, the clavicular portion was wanting; neither does Sandifort mention any clavicular portion in the adult dissected by him.
In the Magot, a thin muscular slip, distinct from the Pect. Major, and beneath it, was found, which arose from the lower ribs, and terminated in a thin membranous expansion, which appeared to be inserted partly into the aponeurosis of the arm, and partly into the intermuscular septum and the humerus.
In Man, it is by no means unfrequent to find the sternal portion divided into two or more parts; the arrangement met with in the Magot is described in the human subject by Theile;[2] and Mr. Hallett[3] mentions a very similar one as occurring in man.
The Pectoralis Minor presented the same appearance as in man; in the Gorilla, Duvernoy states that it is divided into two portions; one passing in front of, the other behind the laryngeal sac.
The two heads of the Biceps remained distinct until they reached
