MUSCULAR SYSTEM OF AVES. 95 



The levator scapulce arises by digitations from the pleura- 

 pophyses of the last cervical, and the first two dorsal vertebraj ; 

 it is inserted into the posterior part of the dorsal edge of the 

 scapula, which it pulls forwards. In the Apteryx it seems to be 

 the most anterior portion of the series of fasciculi composing the 

 serratus magnus anticus. This muscle, ^^. 35, 21, is most de- 

 veloped in birds of prey ; it arises by large digitations from three 

 or four of the middle ribs, and converges to be inserted into the 

 extremity of the scapula. 



The serratus parvus anticus arises by digitations from the first 

 and second ribs, and is inserted into the commencement of the 

 inferior margin of the scapula. This is the largest of the muscles 

 of the scapula in the Penguins. 



A muscle, which may be regarded either as a portion of the 

 pectoralis minor or as the analogue of the suhclavius muscle, 

 arises from the anterior angle of the sternum, and is inserted into 

 the external margin of the sternal extremity of the coracoid bone. 



The sujira-spinatus, ib. 22, arises from the anterior and outer 

 part of the humeral end of the scapula, and is inserted behind 

 the largely developed radial crest of the humerus. 



The muscle which seems to represent both the infraspinatus 

 and teres major, ib. 23, has a more extensive origin from the 

 scapula, and is inserted into the ulnar tuberosity of the humerus, 

 where it is closely attached to the capsule of the shoulder-joint. 



The subscapularis arises from the anterior part of the inner sur- 

 face of the scapula, and is inserted into the ulnar humeral tubero- 

 sity. It is divided into two portions by the pectoralis minor. 



The latlssimus dorsi, ib. 24, is but a feeble muscle in Birds, and 

 is constantly divided into two distinct slips. The anterior portion 

 arises, more superficial than the trapezius, from the spines of the 

 four or five anterior dorsal vertebrae, and is inserted near the 

 tendon of the deltoid into the outer side of the humerus. The 

 posterior slip comes from the spines of the dorsal vertebrae above 

 the origin of the broad abductor femoris, ib. 40, and sometimes 

 from the anterior margin of the same muscle, and is inserted 

 by a broad and thin tendon immediately in front of the pre- 

 ceding portion. 



The deltoides, ib. 26, arises from the anterior part of the scapula; 

 also in Volitores and Cantores from the acromial end of the furcu- 

 lum and the coraco-furcular ligament : a distinct fasciculus from 

 the inner angle of the humeral end of the scapula passes over 

 the OS humero-scapulare, or the humero-scapular ligament, to be 

 inserted into the angle of the pectoral ridge ; this portion is large 



