164 INTERNAL OR MUCOUS COAT OF THE URETHRA. 



for if it be injected with colored wax, and corroded in the 

 usual manner, the injected matter will exhibit an appearance 

 which has the strongest resemblance to a convoluted vessel, 

 like the vas deferens in the epididymis.* 



The Canal of the Urethra, 



Which conveys the urine from the bladder, is a very impor- 

 tant part of the urinary organs. It consists of a vascular mem- 

 brane with a smooth surface, which is perforated by the orifices 

 of many mucous follicles, some of which are of considerable 

 size. It is extremely sensible, and has so much power of con- 

 traction, that some persons have supposed muscular fibres to 

 exist in its structure. 



It is differently circumstanced in different parts of its course. 

 While surrounded with the prostate it adheres firmly to that 

 body, seeming to be supported by it ; and here its diameter is 

 larger than it is farther forward. On the lower or posterior 

 side of this portion of the urethra, is an oblong eminence, called 

 Verumontamim, or Caput Gallinaginis, which commences at 

 the orifice of the urethra, and continues throughout the whole 

 portion that is surrounded by the prostate gland, terminating 

 at the point of that body. The posterior extremity of this 

 tubercle begins abruptly, and soon becomes thick and large ; 

 anteriorly it gradually diminishes to a line, which is sometimes 

 perceptible for a considerable distance in the urethra, in a 

 straight forward direction. In the upper edge or top of this 

 body is a groove, which is produced by a mucous follicle ; on 

 the lateral surfaces, anterior to the middle, are the orifices of 

 the common ducts of the vesiculae seminalis, and vasa deferentia, 

 (see page 154,) which are sufficiently large to receive a 

 thick bristle. Near these, on each side, are five or six smaller 

 orifices of the excretory ducts of the prostate gland. At the 

 distance of an inch before the extremity of the bulb of the 



* Mr. Hunter says, " that the corpus spongiosum urethrse and glans penis 

 are not spongy or cellular, but made up of a plexus of veins. This structui:p is 

 discernible in the human subject ; but is much more distinctly seen in many 

 animals, as the horse,"' &c. — h. 



