The Uterus Masculinus

The uterus masculinus or prostatic utricle is a rudimentary structure of variable size and form, situated centrally on the posterior part of the dorsal surface of the bladder. When well developed, it consists of a median flattened tube, some three or four inches (ca. 7.5 to 10 cm.) long, and about half an inch (ca. 1 to 1.5 cm.) wide, the anterior part of which lies in the urogenital fold and gives off two slender processes or cornua; the latter curve forward and outward in the fold a variable distance, being sometimes traceable as far as the anterior end of the ampulla of the vas deferens. The posterior extremity of the tube passes under the isthmus of the prostate, and opens into the urethra on the summit of the colliculus or joins an ejaculatory duct. It has a muscular coat and a mucous lining. In many cases it consists merely of a very small central tubule with a blind anterior end, or a band, not at all sharply marked off from the adjacent tissue; in other cases it cannot be recognized. It is interesting chiefly as being a remnant of the ducts of Müller and the homologue of the uterus and vagina.