264 Ross Granville Harrison 



then it dips behind the tendon of the m. tarsaHs posticus and may 

 be followed for some distance through the tarsus. I have been 

 unable to trace it out into the nn. interstitiales plantares. 



The normal transplanted, or "euneurogenic" limbs (Fig. 13) 

 receive nerves derived for the most part from the eighth spinal 

 nerve. The seventh gives off a twig to the skin which becomes 

 the r. cutaneus femoris lateralis of the primary limb; this nerve 

 is, however, somewhat out of place. The main nerve (from the 

 eighth) runs in between the pelvic cartilages of the primary and 

 accessory limbs in three branches, one of which is considerably 

 larger than the others. This gives rise to the sciatic nerves of the 

 two limbs and to the crural of the secondary. The other two run 

 distally between the pelvic cartilages, and emerge in the skin of 

 the inner side of the two limbs becoming in each the r. cutaneus 

 femoris posterior. 



Into the primary limb the greater part of the fibers of the main 

 trunk enter as the sciatic, which almost immediately gives off a 

 stout r. profundus posterior which takes its normal course (Fig. 

 13). The sciatic may be clearly followed to the knee, breaking 

 up into two main divisions, the peroneal and tibial. Below the 

 knee the details of its distribution have not been studied. 



The accessory limb receives nerves which are considerably 

 smaller. The crural arises from the main trunk intended for 

 the two limbs before this divides into the two nn. ischiadici. This 

 nerve skirts along the surface of the m. iliacus internus and may 

 be followed as far as the m. pectineus. As the n. ischiadicus, 

 which is smaller than that of the primary limb, enters the accessory 

 limb it gives off an aberrant branch which runs to the skin over- 

 lying the m. glutaeus magnus. There is no nerve of this size in 

 the normal limb at this place. Higher up, /. e., before the sciatic 

 actually enters the limb it gives rise to a small r. profundus posterior 

 which passes ventral to the m. piriformis and may be traced along 

 the dorsal surface of the mm. gemellus and quadratus femoris. It 

 is not nearly so large as the corresponding nerve of the primary 

 limb but it is normally situated with respect to the other structures 

 of the limb. 



The sciatic nerve may be followed through the thigh. It divides 



