210 Study of the Abdominal and Border-Nerves in Man 



might be expected from the intimate relations existing between the 

 development of the spinal axis, the position of the posterior limb, and 

 the type of distribution of the border-nerves, we find also that when the 

 lumbo-sacral plexus has a more anterior position than usual, the border- 

 nerves generally axise from an anterior set of spinal nerves; and that 

 when the lumbo-sacral plexus has a posterior positidn, the border-nerves 

 likewise arise from a distal set of spinal nerves/ 



Origin of the Hypogasteic Neeve. See Table X. — We shall now 

 consider in turn the individual border-nerves, beginning with the 

 hypogastric. 



In 6 instances, 2^ of the number studied, the hypogastric nerve arose 

 from the 19th and 20th spinal nerves; in 91 instances, 32^, from the 

 20th; in 98, 34^, from the 20th and 21st; and in 92, 32^, from the 21st. 

 In 106 instances, 37^, the hypogastric nerve arose from the ventral trunk 

 of the 20th spinal nerve; in 190 instances, 69^, from the 21st; in 9 in- 

 stances, 3^, there were two hypogastric nerves. 



In the table the term " dorsal origin " is used to indicate the separa- 

 tion of the hypogastric nerve from the main ventral trunk of the 

 twelfth thoracic nerve near the spinal axis. See Fig. 1, A. The term 

 " ventral origin " is used to indicate the separation of the hypogastric 

 nerve from the main ventral trunk after the latter has extended well 

 into the abdominal wall. See Fig. 1, C. The hypogastric has a dorsal 

 origin from the twelfth nerve in 40 instances, and a ventral origin in 

 43 instances out of the 83 in which these conditions were tabulated 

 distinctly. 



Oeigin of the Iliac Neeves. See Table XI. — By the term " iliac 

 ,nerve " is meant a nerve which passes over the crest of the ilium to be 

 distributed on the lateral surface of the hip. Only those nerves have 

 been called "iliac nerves" the distribution of which is entirely distal to 

 the level of the iliac crest. In addition, the lateral branches of the more 

 distal intercostal nerves often extend in their distribution from the 

 region of the abdomen over the lateral region of the hip. 



In 3 instances, 1^ distinct iliac nerves Avere given off from the 19th 

 spinal (11th thoracic) nerve; in 110 instances, 40^, iliac nerves were 

 derived directly from the 20th spinal nerve; and in 76 additional in- 

 stances, 27f^, from the 21st, after the latter had received a branch of 



8 The relation between the lumbo-sacral plexus and the development of the spinal- 

 axis has been pointed out elsewhere. — Bardeen and Elting, op. cit. p. 203. 



