MUSCLES AND FASCLE OF THE PERINEUM. 101 



ternal margins of the ramus of the ischium, and of the pubes, 

 and proceed upwards : just before the union of the crura of the 

 penis, they end in a flat tendon which is lost on the side of the 

 corpus cavernosum of the penis.* 

 Its use is not well understood. 



The Musculus Accelerator Urince, 



Lies on the bulb and back part of the corpus spongiosum 

 urethras: it is a thin muscle, consisting of oblique fibres. 



It arises by a pointed production from the side of the body of 

 the penis; its origin is continued obliquely across the inferior 

 surface of the crus penis, where the latter begins to form the 

 body of the penis. It arises, also, for an inch from the inner side 

 of the ramus of the pubes, between the crus penis and the tri- 

 angular ligament of the urethra. The muscles of the opposite 

 sides are inserted into one another by a white line, which marks 

 the middle of the bulb of the urethra; and by a point, into the 

 anterior extremity of the sphincter ani, where they are joitfRd 

 by the transversi perinei. 



In order to see the origin of these muscles very distinctly, 

 separate them from each other in the middle line, and dissect 

 them from the corpus spongiosum. Cut transversely through 

 the corpus spongiosum about three inches before the triangular 

 ligament, and dissect it clearly from the corpus cavernosum, 

 turning it downwards so that it may hang by the membranous 

 part of the urethra. By putting the two accelerators on the 

 stretch, it will be seen that besides the origins mentioned, they 

 arise, also, from each other by a tendinous membrane that is 

 interposed between the corpus spongiosum and cavernosum ; so 

 that they literally surround the back part of the urethra, consti- 

 tuting a complete sphincter muscle for it. This account of the 

 accelerator urince being peculiar to myself, is adopted from a 

 strong analogy between it and the sphincter vaginae. 



The two muscles are considered by M. Chaussier as forming 



* The late Dr. Lawrence informed me that he hud frequently found muscular 

 fibres between the bone and the crus penis. 



10* 



