AND PHYSIOLOGY. 



123 



Fig. 139. 



A View of the Second Layer of Muscles of the Back. 1, Trapezius. 2, A portion of 

 the Tendonous ellipse formed by the Trapezius on both sides. 3, Spine of the Scapula. 

 4, Latissimus Dorsi. 5, Deltoid. 6, Infra-Spinatus and Teres Minor. 7, External Ob- 

 lique of the Abdomen. 8, Gluteus Medius. 9, Gluteus Magnus of each side. 10, Leva- 

 tor Scapulje. 11, Khomboideus Minor. 12, Ehomboideus Major. 13, Splenius Capitis. 

 14, Splenius Colli. 15, A portion of tiie Origin of the Latissimus Dorsi. 16, Serratus In- 

 ferior Posticus. 17, Supra-Spinatus. IS, Infra-Spinatus. 19, Teres Minor. 20, Teres 

 Major. 21, Long Head of the Triceps Extensor Cubiti. 22, Serratus Major Anticus. 23, 

 Internal Oblique of the Abdomen. 



The largest muscle of the back (hence the name Dorsal) is 

 of value to move the arms. It has its origin from the lum- 

 bar and sacral vertebrae, and the posterior third of the crest 

 of the ilium, and is inserted by a short tendon into the upper 

 extremity of the humerus. The action of this muscle brings 



Give the origin and insertion of the Dorsal muscle. State its action. 



