PUDIC ARTERY AND NERVE. 399 



merit, and divides into the arteries of the cavernous structure and dorsum 

 of the penis. In this course it is placed beneath the constrictor urethras, 

 and is accompanied by vena? comites and the pudic nerve. Its offsets are 

 subjoined : 



a. The artery of the bulb of the urethra is a branch of considerable 

 size, and arises near the base of the triangular ligament. Passing almost 

 transversely inwards between the layers of that ligament, about half an 

 inch from the base, the artery reaches the back of the bulb, and enters the 

 spongy structure. Near the urethra it furnishes a small branch to Cow- 

 per's gland. 



The distance of this branch from the base of the ligament will be in- 

 fluenced by its origin near the front or back of the perinatal space. If the 

 vessel arises farther behind than usual, it may be altogether below the 

 ligament, and may cross the front of the ischio-rectal fossa, so as to be 

 liable to be cut in the operation of lithotomy. 



b. Deep muscular branches (d). As the artery is about to enter between 

 the layers of the triangular ligament it furnishes one or more branches to 

 the levator ani and sphincter, and fine twigs through the ligament to the 

 constrictor and the urethra. 



c. The artery of the cavernous structure of the penis (c) (art. corporis 

 cavernosi) is one of the terminal branches of the pudic. At first this small 

 vessel lies between the crus penis and the bone, but it soon enters the eras, 

 and ramifies in the cavernous structure of the penis. 



d. The dorsal artery of the penis (h) is in direction and size the con- 

 tinuation of the pudic ; it runs upwards between the crus and the bone, 

 and reaches the dorsum of the penis by passing through the suspensory 

 ligament. Its distribution with the accompanying nerve is noticed at page 

 408. It is much smaller in the female than in the male. 



Accessory pudic artery. In some cases the pudic artery is not large 

 enough to supply the branches above described to the penis and the ure- 

 thra. One or more offsets will be then contributed by an accessory vessel, 

 which leaves the pelvis in front by piercing the triangular ligament. The 

 source of this accessory artery is the internal iliac. 



The pudic veins, two in number, have the same connections as the 

 artery ; they receive similar branches, except that the dorsal vein of the 

 penis does not join them. 



The PUDIC NERVE has been examined in the ischio-rectal fossa (p. 391). 

 In the anterior half of the perinasum it is much diminished in size, in con- 

 sequence of the emission of the large perinatal branch, and courses with 

 the artery between the layers of the triangular ligament ; near the pubes 

 it pierces the ligament (fig. 131, 3 ), and is continued to the dorsum of the 

 penis with the dorsal branch of the pudic artery ; its termination is de- 

 scribed at page 408. The deep muscles and the corpus spongiosum are 

 supplied by the following branch. 



Perinceal branch (p. 391). Arising in the ischio-rectal fossa it supplies 

 superficial nerves, and ends near the base of the triangular ligament in 

 deep muscular offsets: some of these (fig. 131, 2 ) pass beneath the trans- 

 versalis, and piercing the triangular ligament, supply the muscles within 

 it. A long slender branch, nerve of the bulb, is distributed like the artery 

 to the spongy structure investing the urethra : its filaments reach some 

 way on the surface before disappearing in the corpus spongiosum urethra?. 



Parts cut in the lateral operation of lithotomy. This operation for stone 

 in the bladder may be divided into three stages, viz., cutting down to the 



