524 SCIATIC NERVE. 



joined by the last lumbar nerve, and by a branch of the fourth 

 sacral, in the formation of the great sciatic nerve. This union 

 constitutes the Sciatic Plexus. 



The anterior branch of the fourth nerve transmits branches 

 to the sympathetic : it also sometimes sends a branch to the 

 united nerves above, or the sciatic plexus. It sends branches to 

 the hypogastric plexus, and to the contiguous muscles. 



The fifth and sixth pairs, which are very small, terminate also 

 in the contiguous muscles and in the integuments. 



From the Sciatic plexus, or the nerves which compose it, sev- 

 eral smaller branches go off. There are generally two which 

 pass off backwards through the ischiatic notch, and are denomi- 

 nated Gluteal, as they are distributed to the glutei muscles. 

 From the lowermost of these a branch descends on the thigh. 



The Pudic nerve, which is appropriated to the organs of 

 generation, also passes off from this plexus, and appears to 

 consist of fibres which are derived from each of the nerves that 

 compose it. It proceeds between the sacro-ischiatic ligaments 

 and divides into two branches an inferior and a superior. The 

 inferior passes between the erector penis and the accelerator 

 urinae muscles, and is distributed to those muscles, to the bulb of 

 the urethra and the interior of that canal, to the scrotum and 

 dartos. 



The superior proceeds along the os pubis to the symphysis, 

 and passes between the bone and the body of the penis to the 

 dorsum. A considerable branch accompanies the artery on the 

 dorsum, and terminates by many ramifications, on the glans 

 penis ; after sending branches in its course to the integuments 

 generally, and to the prepuce. 



In females, the Inferior pudic nerve or perineal proceeds 

 along the external labia pudendi to the mons veneris, sending off 

 many ramifications in its course. 



The Superior pudic nerve proceeds as in males, along the 

 branch of the pubis to the superior surface of the clitoris, and 

 terminates principally upon the extremity of that organ. 

 A nerve called the Lesser Sciatic, passes out through the 

 sciatic notch below the pyriformis muscle. It gives off some 

 muscular branches to the glutei muscles, and two that are 



