There exists considerable variety of opinion as to the method of closure of the bladder. Rosenthal and von Wittich no longer regard the sphinc ter vesicoe (so-called) as a muscle which is kept by the nervous system in a tonic state of contraction; they look upon it as intended to completely empty the urethra of urine. It is assumed on the other hand, that the ring of elastic fibres prevents the outflow of the urine through the urethra; but that as soon as the tension of the bladder wall, from the contained urine, overcomes the elasticity of these parts, a drop of urine attains the urethra, the desire to empty the bladder is set up, and the act now occurs voluntarily. But the cases of healed urethro-vesico-vaginal fistula, when the neck of the bladder and the upper part of the urethra have been de stroyed, and when the lower portion of the canal has sufficed to retain the urine, shows that the muscular tissue of the urethra, is sufficient, of itself, to prevent an involuntary outflow.
The bladder, when empty, lies against the symphysis pubis, projecting somewhat above its highest point. Its wall is about inch thick, and its shape according to Furst is such, that a short portion (iag inch) is vertical, a longer portion (1 inch) is arched from the symphysis, and a portion half an inch in length stretches to the level of the internal os uteri. The form of the cavity is, therefore, that of a narrow slit with three processes, of which the anterior is the longest.' According
to B. S. Schultze,' the form of the empty bladder (comp. Fig. 2) is slightly different. The anterior vaginal wall is attached to the lower posterior one of the bladder; and where this ends, begins the attach ment of the bladder to the anterior uterine wall, which reaches to the point where the peritoneum is reflected from the uterus on to the bladder, up to or a little beyond the height of the os internum. The posterior vesical wall, when the organ is empty, forms a sharp angle at the point where the vaginal attachment merges into the uterine attach ment; so that if we imagine the woman to be standing upright, the lower wall of the bladder will be attached to the vagina, and the upper wall to the uterus. When the bladder is moderately full, so that it is raisad but a little above the entrance of the pelvis (comp. Fig. 3, Hasse,), the sinking of the posterior vesical wall, to which Kohlrausch has drawn at tention, is well seen. This same drawing effectively demonstrates the flattening of the bladder by the uterus, and the manner in which the bladder, with the round ligaments, and the peritoneal covering, holds the uterus in place. Berry IIart has lately affirmed that the normal empty female bladder shows an oval figure on median section, and forms with the urethra a more or less extended canal; its vault is therefore convex. The arrangement of the muscular tissue would favor this idea. Only in the puerperal state is the Y shape the rule.'