212 



the spinal nerves varies considerably from that there described. In 

 all the plexuses included under type C, the XXIV spinal nerve sent 

 the bulk of its fibres to the sacral plexus and half or less to the 

 femoral and obturator nerves. 



In three instances bundles of fibres could be followed from the 

 XX spinal nerve into the lateral cutaneous nerve and in two instances 

 into the femoral as well. In 54 instances the XXI spinal nerve 

 contributed to the lateral (external) cutaneous nerve and in 43 instances 

 slightly to the femoral and obturator nerves. In 20 instances the 



XXII spinal nerve was the first to furnish fibres to the latter nerves. 

 It is probable that most of the fibres derived from the XXI spinal 

 nerve are, in these plexuses, distributed to the skin on the anterior 

 surface of the thigh. 



The earlier records as to the last spinal nerve to supply the 

 peroneal nerve in these plexuses are less definite than one could 

 wish, owing to the fact that the peroneal and tibial nerves were not 

 always carefully separated back to their origin. Out of the 31 plexuses 

 observed during the years 1898 — 1900, in 18 instances the XXVII spinal 

 nerve contributed a slight branch to the peroneal nerve, in 13 instances 

 no such branch was found. 



In 5 instances a few fibres seemed to be contributed from the 



XXIII spinal nerve to the sacral plexus. 



II. Median or "normal" origin of the nerves of the limb. 

 Type D. The plexuses included under this type have already 



been considered (see p. 134). 



III. Distal or "posterior" origin of the nerves of the limb. 

 In types E to G we have a more distal set of nerves than usual 



contributing to the nerves of the limb. 



Under type E we have included 18 plexuses in which the nerves 

 of the limb are supplied by the XXII to the XXVIII spinal nerves 

 and in which the XXV spinal nerve contributes to the femoral or 

 obturator nerve or to both, while the XXIV may or may not contribute 

 to the sacral plexus. In 17 instances the XXV spinal nerve contributed 

 to the formation of the femoral nerve, in 14 instances to the formation 

 of the obturator nerve; in 7 instances the XXIV spinal nerve contributed 

 to the sacral plexus. In one instance seen duiing 1898 — 1900, out 

 of the nine instances observed, the XXVIII spinal nerve furnished fibres 

 to the peroneal nerve, in all others the XXVII nerve seemed to be 

 the last to furnish such fibres. 



Under type F we have included 15 plexuses in which the XXIV 

 spinal nerve was the furcal nerve and in which the XXIX spinal 



