LIGAMENTS AND MUSCLES OF THE HORSE. 58 



8. Obturator internus. 



Origin.— From the upper surface of the pubis and ischium, 



around the obturator foramen. 

 Insertion. — In the trochanteric fossa, by a tendon common to it 



and the pyriformis. 

 Action. — To rotate the thigh outward. 



9. Pyriformis. 



Origin. — From the inferior surface of the ilium. 



Insertion.— In the trochanteric fossa. 



Action. — Same as preceding. 



Sote. — The two preceding muscles have a common tendon which 



emerges from the pelvic cavity by the lesser sacro sciatic 



foramen. 



10. Gemellus. 



Origin. — From the external border of the ischium. 



Insertion — In the trochanteric fossa. 



Action. — Same as preceding. 



^"o^e. — The Gemellus is a single muscle in the horse, consisting 

 of anterior and posterior rounded fasciculi, united by a thin 

 median portion, concealed by the common tendon of the 

 obturator internus and pyriformis. 



ANTERIOR TIBIAL REGION. 



1. Extensor Pedis. 3. Flexor Metatarsi. 



2. Peroneus. 



1. Extensor Pedis. 



Origin. — From the pit bet ween the external condyle and troch- 

 lea of the femur, in common with the tendinous portion of 

 the flexor metatarsi. 



Insertion. — To the pyramidal process of the os pedis. 



Action. - To extend the foot, pastern, and the fetlock, and to 

 flex the hock. 



Note. — At the front of the hock, the tendon is bound down by 

 three fibrous bands. About the middle of the metatarsus, 



