VESICULIE SEMINALES. — These are a pair of sacculated organs, peculiar to the male, situated behind the bladder, be tween it and the rectum. In man they ap pear, externally, as multilocular cysts about two inches in length and three quarters of an inch in their greatest breadth. Their shape is fusiform ; their larger ends diverging from one another, and their smaller ends con verging so as almost to meet. These smaller ends are surrounded by the prostate, and are directed slantingly forwards, as well as down wards and inwards. Along their inner sides pass the vasa deferentia, with which they join, by a narrow outlet, at the base of the prostate.
The vesicula' are invested by a fascia de rived from the prostate, which can be removed by careful dissection, and then they are found to consist of a blind tube of about the calibre of a small goose quill doubled upon itself again and again, all the gyrations being held together by cellular tissue, so as to give the appearance of fusiform multilocular sacs. A little careful maceration will enable the anatomist to unravel these gyrations, when each vesicula will sometimes be found to be one simple cmcal tube about six or eight inches long, or, more frequently, there will be three or four cmcal diverticular appendages to the main tube, in which case the greatest length (that of the central main tube) will be very much less. This tube has a very much
smaller calibre for a short distance from its junction with the vas deferens than else where. The narrow portion is straight, and is commonly called the duct of the vesicuke seminales.
These vesicles are found to contain a synovia-like brownish mucus, the nature of which we shall have to inquire into presently, when we treat of their function.
The fascia that invests the mass of gyra tions, like a fusiform bag, contains a great proportion of involuntary muscular fibre, and there is also a large admixture of involuntary fibre in the proper parietes of the tube. It is, of course, lined throughout with a mucous surface, which has a faint reticular marking, like that of the stomach in some animals, and is evidently glandular, or secreting.