The _diagnosis_ of retroversion is, generally speaking, not very difficult, the os uteri tilted up behind the symphysis pubis, and the fundus forced downwards and backwards between the vagina and rectum, are sufficiently characteristic of this displacement. We cannot agree with Dr. Dewees that it can easily be mistaken for prolapsus uteri; in cases of sudden prolapsus which has been caused by great violence, there will be, it is true, intense pain in the pelvis, with sensation of forcing and tearing in the direction of the broad and round ligaments; there will also, probably, be inability to evacuate the rectum and bladder; but then the examination, per vaginam, will present such a totally different condition of parts as to preclude all possibility of mistake: the vagina merely shortened, neither altered in direction or form; the os uteri at the lower part of the tumour, which is in the vagina; the mobility of the tumour itself, all conspire to show that the case is one of prolapsus not retroversion. We occasionally meet with cases of retroversion where the os uteri, although carried more or less upwards and forwards, is not forced, to that extreme height behind the symphysis pubis as is usually observed. Instead of looking towards, or rather above, the symphysis, the os uteri itself looks downwards, the neck or lower part of the body of the uterus being bent upon the fundus like the neck of a retort.[53] If, under such circumstances, we cannot satisfy ourselves as to the existence of pregnancy, we might easily be led to form an erroneous diagnosis, and to conclude that some tumour had forced itself down into the hollow of the sacrum, between the rectum and vagina, and had thus pushed the uterus upwards and forwards, above the brim of the pelvis. An extra-uterine ovum of the ventral species may occupy this situation, but its slow and gradual growth, its greater softness and elasticity, and the slight degree of uterine displacement produced in its early stages, would enable us to ascertain its real character. The same would hold good to a certain extent with an ovarian tumour, although in all probability this would produce more or less displacement of the uterus to one side. The danger in retroversion of the uterus chiefly arises from the distension or rupture of the bladder, and from the gangrenous inflammation which may then take place, not only in it, but also in the uterus and neighbouring parts. The very displacement itself is sometimes immediately attended by alarming symptoms, such as faintness, vomiting, cold sweats, weak irregular pulse, as seen in cases of inversion or strangulated hernia. In some cases the suffering at first is but trifling, and only increases in proportion to the degree with which the bladder is distended.