528 Zoological Society. 



small. A muscle arises from the outer and upper fourth of the mem- 

 brane between the furculum and os coracoides j it passes upwards, 

 but internal to the capsular ligament of the joint ; and is inserted, 

 tendinous, immediately above the insertion of the pectoralis minor. 

 Another muscle arises from the external inferior third of the os co- 

 racoides, from the angle and costal part of the sternum, and from 

 the fascia of the pectoralis major for about the length of an inch - 7 

 passing upwards it forms a round tendon about 4 of an inch from 

 the shoulder, which passes over the joint and under the supraspi- 

 nous, and is inserted into the external edge of the foramen at the 

 head of the humerus. The supra-spinatus is small, and arises fleshy 

 from the superior edge of the scapula, near the glenoid cavity ; it 

 passes round and constricts the ligament of the joint, and is in- 

 serted, tendinous, into the humerus, immediately anterior to the 

 muscle last named. 



" I will here notice, before proceeding to the remaining muscles, 

 a loop through which several of the muscles pass. It arises flat from 

 the infero-anterior edge of the scapula, just below the glenoid ca- 

 vity, and passing upwards and outwards for about an inch, is then 

 doubled upon itself, and attached to the same part from whence it 

 arose : there is no admixture of its fibres. 



" A muscle arises from the fascia which covers the last rib and the 

 outer edge of the external oblique, passes upwards and through the 

 loop, and is inserted into the lower part of the external edge of the 

 foramen situated at the posterior part of the head of the humerus. 

 The latissimus dorsi arises from the last cervical and first five dorsal 

 vertebra, and forms a tendon, which passes through the loop and is 

 inserted immediately below the preceding muscle. The infraspi- 

 natus arises fleshy from the whole external surface of the scapula 

 below the upper third, and is inserted into the large tubercle of the 

 humerus. A muscle arises from that part of the inner edge of the 

 os coracoides which is produced ; it passes obliquely upwards and 

 outwards behind the os coracoides, to which it is attached ; and is in- 

 serted tendinous into the anterior tubercle of the humerus. The 

 deltoides arises from the posterior part of the projecting edge of the 

 scapula, and from the scapular process of the clavicle ; passing over 

 the shoulder-joint, it is inserted into the anterior part of the middle 

 tubercle of the humerus. The subscapularis arises from the internal 

 surface of the scapula ; it passes upwards, and is inserted into the 

 posterior part of the middle tubercle of the humerus. The teres minor 

 arises from the whole width of the posterior surface between the 

 glenoid cavity and the end of the upper third of the scapula ; it passes 

 in the groove, and is inserted into the inferior part of the large tu- 

 bercle of the humerus. Of the triceps extensor cubiti the long head 

 arises immediately above the origin of the teres minor, and passing 

 down on the external side of the humerus, it is joined by the second 

 head, arising from the internal part of the large foramen ceecum of 

 the humerus ; these two unite about the middle of the arm, and are 

 joined by the third head, which arises from the two inferior thirds of 

 the posterior edge of the humerus till within 8 lines of the joint : it 



