14 THE SURGICAL ANATOMY OF THE HORSE 



the Plate the Ugament is relaxed and dips inwardly between the patella 

 and the tibia, owing to the fact that the former is placed at the lower 

 end of the trochlea since the quadriceps muscles are relaxed. 



The External Lateral Ligament of the Stifle (7). — This is repre- 

 sented as being attached to the external surface of the outer condyle 

 of the femur above and to the head of the fibula below. The fibres of 

 the peroneus muscle are seen to arise from this ligament. 



At the front of the hock the three transverse fibrous bands are shown 

 which hold the tendons playing over this part in position (15, 17, and 19). 



The Great Suspensory Ligament (30) first becomes visible about three 

 inches below the head of the small metatarsal bone, the upper portion 

 of the ligament being concealed by the greater thickness of this bone. 



Above the fetlock the ligament divides into two parts, and the outer 

 division may be followed obliquely across the outer aspect of the fetlock- 

 joint to the front of the limb, where it becomes united to the tendon of 

 the extensor pedis, as in the fore limb. 



The Muscles and Tendons 



The Quadriceps Extensor Cruris (i). — These are the muscles which 

 clothe the anterior and , lateral surfaces of the shaft of the femur. 

 Only the outer half of the inferior third of these muscles is shown, 

 since the limb has been severed across the line of division between 

 the middle and inferior thirds of the femur. The muscles are inserted 

 on the anterior face of the patella. 



They are the great extensors of the stifle joint, their action being 

 transmitted to the limb through the medium of the straight ligaments of 

 the patella. 



They are supplied by the anterior crural nerve, and are the muscles 

 which are affected in crural paralysis. 



The Biceps Femoris (3). — This muscle is in three divisions : one is 

 inserted into the patella, another into the tibial crest, and the third into 



