Stowell, Au'rves in the Domestic Cat. 293 



Pub.), and giving numerous filaments in plexiform relations 

 over the hypogastric integument. The caudal division of 

 the third lies entad of the cephalic division of the fourth, 

 and ectad of the cephalic ramus of the iliolumbar artery; 20 

 mm. from its origin it crosses a ramulus of the caudal ramus 

 of the same artery as the arteriole perforates the lateral 

 border of the M. abdominis rectus. The nerve gives filaments 

 to the transverse (Fig. trans.) and to the ental oblique (Fig. 

 M. ent. ) muscles. The caudal division of the fourth lies 

 apposed to the caudal ramus of the ilio-lumbar artery for 15- 

 20 mm.; it passes between the cephalic and the caudal divi- 

 sions of the genito-crural nerve. It innerves the transverse 

 and ental muscles 10—15 '^""ti- dorsad of the region supplied 

 by the caudal division of the third, and terminates in the 

 rectus abdominis muscle. 



The fifths sixth and seventh lumbar nerves are distin- 

 guished from the other lumbar nerves by the plexus (PI. lum- 

 balis) formed by the dorsal or caudal divisions of the ventral 

 nerve trunks. These nerves rapidly increase in size, the 

 seventh being considerably the largest. The union of the 

 divisions or branches just ventrad of the vertebral diapophy- 

 ses forms not only an important part of the lumbar plexus, 

 but constitutes the lumbo-sacral cord of anthropotomy, from 

 which nerves take their ectal origins, v. below. 



N. GENITO-CRURALIS, N. LUMBO-INGUINALIS ; N. PUDENDUS 



EXTERNUS. 



The genito-crural nerve (second lumbar of anthropotomy) 

 has its ectal origin by two roots; the cephalic root seems to 

 be the lateral continuation of the fifth lumbar nerve, the 

 caudal root is a large branch of the sixth lumbar nerve, given 

 off at the foramen of exit centrad of the plexus. The root 

 nerves are inter-related by anastomotic filaments. The trunk 

 formed by the union of the roots penetrates the aponeurosis 

 of the M. psoas, lies upon its ectal surface about 2 mm. 

 laterad of the mes^l border of the muscle, and separates into 



