GO THE ANATOMY OF THE HORSE. 



The Pectixeus (Plate 13). This muscle has a distinctly conical form. 

 It lies posterior to the femoral vessels, and the profunda artery disap- 

 pears beneath it. It arises from the brim and inferior surface of the 

 pubis, and it is there penetrated by the pubio-femoral ligament, from 

 which some of its fibres take origin. Its tapering point is inserted into 

 the shaft of the femur in the neighbourhood of the nutrient foramen. 



Action. — It adducts the limb, and flexes the hip. 



The Adductor Parvus (Adductor In-evis of Percivall) (Plate 13) is situ- 

 ated between the i)ectineus and the great adductor. It arises from the 

 inferior surface of the pubis, and is inserted into the posterior siirface of 

 the femur about its middle. 



Action. — It is an adductor and outward-rotator at the hip-joint. 



The Adductor Magnus {Adductor longtis of Percivall) (Plate 13) 

 arises from the inferior surftvce of the ischium, and from the tendon of 

 origin of the gracilis. It has two insertions, between which the femoral 

 artery passes. 1. Its deeper fibres are inserted into the posterior surface 

 of the femur, on a quadrilateral area above the smooth groove in which 

 the femoral artery rests. 2. Its more superficial and longer fibres are 

 inserted into the forepart of the supracondyloid crest. 



Action. — It is an adductor at the hip. 



The Semimembranosus {Adductor viagnus of Percivall) (Plate 13). This 

 is a muscle of large size. It arises from the lower surface of the ischium, 

 including its tuberosity, and by a small slip from the fiiscia investing 

 the muscles of the tail. It is inserted into the inner condyle of the 

 femur, behind the tubercle for the attachment of the internal lateral 

 ligament of the stifle. 



Action. — Commonly, it is an adductor and extensor of the hip ; but 

 when the femur is fixed, it acts as a lever of the first order, and assists 

 in rearing. 



Directions. — The foregoing muscles must now be cut and partially 

 removed as follows : — 



The semimembranosus is to be cut transversely, an inch or two above 

 its insertion. The muscle is then to be raised upwards from the semi- 

 tendinosus, on which it rests ; and in doing this, branches of nerves 

 from the great sciatic will be found entering it in front. The central 

 portion of the muscle may then be removed, leaving a few inches at its 

 origin. The other muscles must be served in the same way, leaving 

 only short portions at the origin and insertion, except in the case of the 

 adductor parvus and upper half of the adductor magnus, whose 

 common insertion into the back of the femiu- is to be entirely removed. 

 Care is to be taken of the femoral artery where it rests on the bone, and 

 in performing the dissection it will be well to refer to Plate 14 as a 

 guide. In reflecting the upper portion of the great adductor, a branch 

 of the obturator nerve will be found entering its deej) face, after having 



