84 THE VOrAGE OF H.M.S. CHALLENGER. 



me to follow from an accurate reading of Schoepss' description. I am rather inclined, as 

 above noted, to regard Selenka's coraco-brachialis as corresponding to muscle No. 16 of 

 Schoepss' description. 



5. Coraco-hrachialis. 



Soudavier interne, Vicq d'Azjr, 1772, p. 628, No. L 



Der vordere anziehende Armmuskel, Merrern, p. 153, No. 6. 



Coraco-hracJiial, Meckel, torn. vi. p. 39, No. 13. 



Der ohere Hackenarmmitskcl, Schoepss, p. 115, No. 17. 



Coraeo-bracMalis brevis, Selenka, p. 115, No. 41. 



L'accessaire coracoidien du sous scapulaire, Gervais and Alix, p. 23. 



Attachments. — The coraco-brachialis muscle arises by means of a stout tendon from 

 the anterior border and inner or thoracic surface of the sternum, close to the middle line 

 of the bone. As it passes obliquely forwards and upwards it is further attached to the 

 thoracic surface of the strong sterno-clavicular membrane, as well as to the proximal 

 half of the same surface of the coracoid bone. After passing beyond that bone, the 

 muscle ends on a tendon common to it and to the supra-spinatus, by means of which it is 

 inserted into a well-marked bony tubercle, situated upon the inner margin of, and over- 

 hanging the tricipital fossa of the humerus. 



Action. — This muscle depresses the wing at the shoulder joint, and approximates it to 

 the body. In -this respect it co-operates with the pectoralis minor. It acts moreover as 

 an internal rotator of the humerus at the shoulder joint, in which respect it co-operates 

 with the pectoralis major, but opposes the pectoralis minor. 



Relations. — The origin of the muscle is deeply situated under cover of the sternum 

 and coracoid bone. In the axilla the muscle lies parallel to and in contact with the 

 inner border of the pectoralis minor. The axillary vessels and nerves are in contact with 

 it posteriorly. 



Nerve supply. — A twig from the branch which supplies the pectoralis medius. 

 This twig is given off from the larger nerve just before the latter pierces the coracoid 

 bone. 



Remai'hs. — Cuvier mentions the existence of two muscles in birds, either of which 

 may correspond to the coraco-brachialis.^ From want of accuracy of description it is 

 impossible to say which. According to Selenka,^ the coraco-brachialis as above described 

 is included by Tiedemann along with his deltoideus minor and levator humeri. The 

 muscle is not mentioned by Wiedemann. 



' Lemons d'Anatomie Compar^e, torn i. p. 278. 



- Bronn, Classen iind Ordnungen des Thierreichs, Aves, vol. vi. p. 115. 



