The Accelerator Urinae (e, fig. 227). - This muscle extends nearly the whole length of the spongy portion of the urethra, commencing at the ischiatic arch and continuing as far forward as the glans penis. It is composed of a thin layer of fibres arranged around the corpus spongiosum, which it almost completely invests. When it contracts, the walls of the urethra are brought together and its contents are expelled.

Suspensory Ligament of Penis.

Fig. 227. - Suspensory Ligament of Penis.

A, Erector Penis. B, Suspensory Ligament of Penis, c, Retractor Penis. D, Corpus Cavernosum. E, Accelerator Urinae. F, Cremaster Muscle. G, Scrotum. H, Prepuce or Sheath. I, Glans Penis.

The action of this muscle is specially designed to expel the last small portion of urine which remains in the canal after the bladder has emptied itself. It also assists in ejecting the semen from the urethra in the act of copulation.