20 THE SURGICAL ANATOMY OF THE HORSE 



The external popliteal nerve takes a downward course behind the 

 external lateral ligament of the stifle, and divides into the anterior tibial 

 and musculo-cutaneous nerves. 



The Anterior Tibial Nerve (14). — This is one of the terminal 

 divisions of the external popliteal nerve. It runs obliquely down- 

 wards and forwards across the outer aspect of the peroneus muscle, 

 and from one and a half to two inches below the head of the fibula it 

 disappears by dipping between the last-named muscle and the extensor 

 pedis. 



This nerve supplies the extensor pedis, the flexor metatarsi, and the 

 extensor brevis muscles, and it terminates in the skin of the metatarsus. 



The Musculo - Cutaneous Nerve (13). — This nerve also runs 

 obliquely downwards and forwards, but behind the anterior tibial nerve. 

 It gives off a large branch to the peroneus muscle, and then continues its 

 course along the line of apposition of this muscle with the extensor 

 pedis. It distributes cutaneous branches to the front of the hock, and 

 terminates in the skin towards the middle of the metatarsal region. 



The External Plantar Nerve (36). — This leaves the tarsal sheath 

 on the edge of the perforans tendon, being placed behind the unnamed 

 artery which descends from the arterial arch at the tarsus. Near the 

 button of the splint bone it receives the communicating branch from 

 the internal plantar nerve, and it ultimately terminates by splitting up 

 into the anterior, middle, and posterior digital nerves, which are dis- 

 tributed after the manner of the corresponding nerves of the fore 

 limb. 



INNER ASPECT OF LIMB (Plates V. and VI.) 



The Bones 



The inner half of the patella forms the bulging near the upper end of the 

 Plate, which somewhat resembles that caused by the outer half of this 



