876 



THE NERVES. 



posteriorly. Near the inferior extremity of the interstice separating the sartorius 

 and gracilis, it escapes and becomes subcutaneous, dividing into a number of 

 filaments which meet those of the accessory nerve. 



Fig. 473. 



LTJMRO-SACRAL PLEXUS AND INTERNAL NERVES OF THE POSTERIOR LIMB. 



i, 1, Lumbo-sacral plexus ; 2, anterior femoral nerve ; 3, internal saphena nerve ; 4, obturator 

 nerve; 5, originating fasciculus of the great and small femoro-popliteal nerves; 6, superficial 

 ramuscules of the posterior gluteal nerves; 7, great femoro-popliteal nerve; 8, internal pudic 

 nerve ; 9, haemorrhoidal or anal nerve ; 10, internal plantar nerve ; 11, 12, its digital ramifications. 



Note. — In the above figure is seen tlie posterior part of the plexus formed by the nerve- branches which pass 

 through the three first subsacral foramina. That which escapes from the foramen between the sacrum and last 

 lumbar vertebra, only gives a fine branch to this part of the plexus, and sends the greater portion of its fibres, in 

 two cords, to the anterior part. This arrangement is not rare, and is generally seen, we believe, when there are 

 only five lumbar vertebra : as is remarked in the Ass and Mule, and sometimes in the Horse. It will, therefora, 

 be understood that ttie nerve deecribed by us as the first sacral pair becomes a lumbar pair. 



