444 



THE ANATOMY OF THE HORSE 



shoulder joint, and preventing it from being pinched in the motions 



of the joint. The omission of the scapulo humeralis externus by our 



chief EngHsh authority is most unaccountable, 



as it is recognized by all previous writers on 



the subject. 



EXTERNAL SCAPULAR 

 REGION 



Antea spinatus lies upon the anterioi 

 fossa of the scapula. Origin — from the an- 

 terior angle, border, fossa, and anterior sur- 

 face of the spine of the scapula. Insertion — 

 bifid : one part to the outer, the other to the 

 inner tubercle at the head of the humerus, 

 the insertion extending fi'om the tubercular 

 summits to a roughened depression, just 

 posteriorly placed to each. This bifid in- 

 sertion embraces the tendon of the flexor 

 brachii. Action — to draw the scapula into 

 the same line with the humerus. 



PosTEA SPIXATUS is situated upon the pos- 

 terior fossa of the scapula. Origin — from 

 the posterior angle, border, fossa, and pos- 

 terior surface of the spine of the scapula. 

 Insertion — bifid : one portion to the postero- 

 external tubercle ; the other is tendinous, 

 and passes over the postero-external tubercle 

 to a depression just below the outer tubercle. 

 Action — to fix the scapula on the humerus or 

 vice versd. 



Fig. C2. — E ternal View of the Muscles of the Forb 

 Extremity 



Antea spinatus. 



Postea sjiinatus. 



Scapulo humeralis externus. 



Teres externus vel minor. 



Insertion of antea spinatus. 



Humeralis externus and flexor bracliii above. 



Scapulo ulnaris. 



Triceps extensor brachii. 



Extensor metacarjii niagnus. a. c. Tendon of the same 



receiving ligamentous slips. 

 Extensor pedis. 

 Extensor suflfraginis. 

 Flexor metacarpi externus. 

 Flexor pedis perforans. c. Tendon of the same. 

 Fle.xor i)edis perforatus. d. Tcmlon of the same. 



