642 MR.W. F. R. WELDON ON THE [DeC. 18, 



inches long, after which it ends in a tendon. At the junction of the 

 belly with the tendon, a tendinous slip is given off to the humerus. 

 The tendon runs down, at a small angle with the humerus, and joins 

 the aponeurosis over the extensor carpi radialis, where it receives a 

 slip from the tensor patagii longus tendon. 



8. The tensor patagii longus is fused at its origin with the pec- 

 toralis major, and after leaving this it fuses for a short distance 

 with the fleshy part of the tensor brevts. The tendon runs straight 

 to the radial carpal bone, giving off about the middle of the 

 patagium a slip to the aponeurosis over the flexor carpi radialis. 



The result of the arrangements described is, that the tendons of 

 the patagial tensors form a very characteristic figure, shown in fig. 8. 



9. The coracobrachialis externus arises from the tip of the clavicle 

 dorsal to the tensor patagii brevis ; it runs above the coracobra- 

 chialis internus, to be inserted into the middle of the great humeral 

 crest. 



10. The coracobrachialis internus is very small ; it arises from 

 the tip of the coracoid, just ventral to the coraco-scapular articula- 

 tion, and passes over the tendon of the second pectoral to the crest 

 of the humerus. 



11. The external deltoid SiX\se& hy a short flat tendon from the 

 outer face of the scapula, close to the coracoid articulation ; it runs 

 straight to the humerus, into the dorsal face of the crest of which it 

 has an elongated triangular insertion. Close to the origin a second 

 tendon is given off to the scapula (Plate LIX. fig. I, D, Plate LX. 

 fig. 6, DE). 



12. The deltoides internus arises from the tip of the coracoid, 

 external to the long tandon of the biceps, and goes to the ventral 

 side of the humeral crest (Plate LIX. fig. 1, D/). 



13. The triceps arises from the whole posterior face of the 

 humerus, below the pneumatic foramen ; it is fleshy for nearly its 

 whole length, but ends below in a short tendon inserted into the 

 olecranon. 



14. The pectoralis major arises by three heads, the fibres of which 

 are all tolerably distinct : — (1) The superficial head arises from the 

 margin of the clavicle ventral to the origin of the tensor patagii 

 brevis, from the extreme edge of the carina of the sternum along 

 its whole length, and from the whole side posteriorly. The fibres 

 of this head are continuous posteriorly with (2) tlie posterior deep 

 head, which arises from the ventral third of the clavicle, and from 

 the carina beneath the first head. (3) The anterior deep head arises 

 from the ventral face of the sternum beneath (2), and from a small 

 piece of clavicle. 



These various fibres are inserted in a somewhat complicated 

 manner on the head of the humerus. Those from the anterior deep 

 head, remaining quite distinct from the rest, form a strong tendon, 

 which is attached to a tubercle at the base of the deltoid crest of 

 the humerus. From the junction between this muscle and its tendon, 

 a strong ligament passes to the head of the coracoid. From the 

 posterior edge of this tendon, a strong aponeurosis passes over the 



