2qS Journal of Comparative Neurolo(;y. 



criven to the M. vastus internus (V. int.) and to the M. crureus. 

 At the caudal border of the M. vastus internus filaments are 

 given to the muscle; the nerve lies entad of the M. rectus 

 femoris and the adjacent M. vastus externus, whose ental 

 surface it penetrates, accompanied by an artery, and distri- 

 butes filaments from three ramuli to the M. vastus externus. 

 The nerve can be traced around the lateral border of the 

 femur with the internal circumflex (?) artery into the M. 

 pectineus. 



N. obturator. 



Origin. — The obturator nerve (N. Obt. ) has its ectal 

 origin from the lumbo-sacral cord between the seventh 

 lumbar and first sacral nerves, i6 mm. caudad of the anterior 

 crural nerve; in one specimen the origin was by the union of 

 a lumbar (seventh) and a sacral (first) root at the ventral 

 border of the ilium. Its course is caudad, ectad of the ental 

 iliac artery and ventro-mesad of the ventral border of the 

 ilium; it pierces the obturator muscle 30 mm. caudad of the 

 origin of the nerve; it leaves the pelvis through the Fm. 

 obturator, peripherad of which it divides into several rami. 



Principal Ratiii. — The first ramus (N. obturator acces- 

 sorius (?)) is directed ectad to the superposed M. pectineus 

 (Fig. M. Pec). A long ramus bends over the cephalic 

 surface of the origin of the adductor muscle, lies upon the 

 ental surface of the M. gracilis apposed to an arteriole, and 

 innerves the gracilis (Fig. M. grac), in which muscle it may 

 be traced to its aponeurotic insertion at the knee, centrad of 

 which anastomotic filaments relate it with the long saphenous 

 nerve. 



Four rami lie upon the ectal surface of the proximal end 

 of the adductor muscles (MM. magnus and brevis), just peri- 

 pherad of the foramen, in which muscles they terminate. 



Entad of the M. adductor longus, between it and the M. 

 adductor brevis, two ramuli cross the M. adductor brevis and 

 are distributed to the M. adductor magnus, attended by rami 



