734 URINARY ORGANS. 



is contracted. Small papillae are found upon it, near the orifice ; and its epithe- 

 lial lining is of the columnar variety, excepting near the meatus, where it is 

 laminated. 



The muscular coat consists of two layers of plain muscular fibres, an external 

 longitudinal layer, and an internal circular. The muscular tissue is most abundant 

 in the prostatic portion of the canal. 



A thin layer of erectile tissue is continued from the corpus spongiosum round 

 the membranous and prostatic portions of the urethra to the neck of the bladder. 



