Fig. 357. 



776 



The longest and thickest of these goes to the quadratus femoris. Tha 

 passing to the obturator internus re-enters the pelvic-cavity by the small 

 ischiatic notch, and ascends to the vicinity of the ilio-sacral articulation. 



3. BRANCH TO THE ISCHIO-TIBIAL 

 OR POSTERIOR CRURAL MUSCLES. 

 This branch is thick and short ; it 

 arises from the bend formed by the 

 great femoro-popliteal nerve at the 

 gemini muscles, and soon divides into 

 several ramifications which are dis- 

 tributed to the short portion of the 

 triceps cruris, the middle and inferior 

 parts of the semitendinosus, and into 

 the semimembranosus. Some of the 

 filaments destined to the latter muscle 

 pass between it and the great adductor 

 of the thigh, in which they partly 

 terminate (Fig. 356, 12). 



4. EXTERNAL SAPHENOUS NERVE. 

 This branch commences at from 2 

 to 6 inches from the point where the 

 great sciatic nerve dips between the 

 gastrocnemii muscles. It is placed 

 on the external gastrocnemius, and 

 descends underneath the special apo- 

 neurotic layer covering that muscle, 

 to the origin of the tendon of the 

 hock. It then receives its accessory 

 nerve the reinforcing filament which 

 comes from the cutaneous branch of 

 the small femoro-popliteal nerve, and 

 is prolonged beneath the tibial apo- 

 neurosis into the channel of the hock, 

 accompanying the external saphenous 

 vein, and following the external 

 border of the fibrous baud that goes 

 to strengthen the tendo-Achillis. In 

 this way, it occupies the same situa- 

 tion outside the hock that the great 

 sciatic does on the inner side. It 

 afterwards passes over the tarsal 



2, Great sciatic nerve; 3, External saphena reg i on an a ,' s expended on the outside 

 nerve: 4, Lxternal popliteal nerve; 5. An- ., -i /i 



terior tibial nerve; 6, Musculo-cutaneous of the metatarsus m several filaments, 

 nerve ; 7, Origin of the peroneal-cutaneous some of which descend to the outer 

 branch ; 8, Accessory J>ranch of the external aspect of the digit (Figs. 356, 13; 



357, 3). 



5. FARCICULI TO THE POSTERIOR 

 TIBIAL MUSCLES. This fasciculus is 



composed of numerous branches, which are detached together from the 

 sciatic nerve on its passage between the gastrocncmii muscles, in the form 

 of a thick short trunk. The muscles of the superficial layer the gastro- 

 cnemii, perforates, and the thin fleshy band, improperly designated the small 

 plantaris by Veterinarians receive ramuscules which are remarkable for their 



! 



EXTERNAL NERVES OF THE POSTERIOR 

 LIMB. 



saphenous nerve ; 9, External plantar nerve 

 with its divisions, which cover the digital 

 artery and vein. 



