having evidently, co-existed. The form of the pelvis in mollities ossium necessarily varies with the peculiar circumstances under which the individual is placed: thus, if her strength allows her to sit up, or even to get about, as is generally the case more or less, the promontory and the pubic bones are gradually pressed towards each other, so that the antero-posterior diameter is greatly diminished:[123] if, however, she is confined entirely to bed for a considerable period, the distortion takes a different and much rarer form. From her lying first on one side and then on the other, the pelvis is laterally compressed; the transverse diameter becomes even shorter than the antero-posterior; and if the disease continues long enough, the pelvis is at length so altered and mis-shapen, that nearly all its original configuration is obliterated. The weight of such a pelvis varies considerably: where the disease has ceased some time before death, and bone earth has been again deposited, there will be little difference in this respect from a natural healthy pelvis; but if the patient has died with the disease in full activity, its weight will be greatly diminished, amounting sometimes only to a few ounces. Mollities ossium, to a slight extent, we believe, is not very uncommon, although cases of extreme deformity from this cause are of rare occurrence. Mr. Barlow states, that "eight cases of this species of progressive deformity have fallen under my notice, in one of which the projection of the last lumbar vertebra at its union with the angle of the sacrum was so much bent forwards into the cavity of the pelvis, that on the introduction of the fore-finger up the vagina, a protuberance was presented to the touch very much resembling the head of the foetus pretty far advanced into its cavity. On carrying the finger a little anteriorly past the projection, I could with difficulty ascertain the head of the child: but on moving it around, the distortion appeared so great, that the whole circumference did not exceed that of a half-crown piece. This occurrence was on the 29th of April, 1792, at which time I delivered the woman with the crotchet, and the bones of the pelvis receded considerably to the impulsive efforts during the extraction of the head of the foetus; yet, notwithstanding, the flexibility of the bones of the pelvis, and the debilitated state of her constitution, she recovered speedily and without interruption." On the 2d February, 1794, being in the neighbourhood, and learning that she was still alive, Mr. Barlow visited her and requested an examination. "I found her unable to walk without assistance, and as she sat, her breast and knees were almost in contact with each other. The superior aperture was nearly in the same state as when I delivered her with the crotchet, but the outlet appeared more contracted, the rami of the pubes overreached, leaving a small opening under the symphysis barely