Upon extending the incisions and looking into the cavity, it presented the appearance of an entire absence of all the abdominal viscera; the spinal column projected at the posterior portion, while above was seen what appeared to be the concave, under surface of the diaphragm, with no trace of liver, stomach, or other viscus. A careful examination of the edges of the incision disclosed the divided walls of the cyst, closely adhered to the abdominal parietes at all points. With a little care, these were gradually torn away, when, behind the tumor, was found the atrophied viscera, crowded and displaced upwards and backward into the smallest possible space. _Pilo-cystic_ or _Dermoid cysts_ may be found containing hair and fatty matters. These appear, in many cases, to be the remains of blighted ova enclosed in the body. They are congenital in their origin, and usually contain some fœtal _debris_, such as portions of bone, teeth, etc. CASE.—_Ovarian Cystic Disease—fatal termination. Autopsy revealing presence of bone and teeth in small cyst._ The following interesting case occurred in the practice of Dr. William A. Read, of this city, from whom the appended statement has been received: Miss ——, aged 42 years, after having been treated by several physicians, came under the care of Dr. Read for the treatment of what was diagnosed as an ovarian tumor. Paracentesis was resorted to, with the result of drawing off a considerable quantity of gelatinous fluid, but without any permanent benefit. The disease pursued the usual course, and the patient finally died of exhaustion. The autopsy revealed a large multilocular tumor, filling a large portion of the abdominal cavity. Upon removing the same from its pelvic attachments, and opening one of the smaller cysts within the broad ligament, the latter was found filled with a quantity of highly offensive fluid, and containing one large, irregular mass of bone, in which were imbedded two well-formed teeth, a smaller piece with one tooth, and nine detached teeth found in the same sac, making twelve in all.[41] The first impression upon the discovery of such remains would naturally be, that the case was one of _extra-uterine pregnancy_; but in this instance, the well known character of the lady was such as to preclude such a theory; while the presence of the unbroken hymen was further evidence of virginity. From the impossibility of conception having been the source of the bony and dental remains found in this and similar cases, the problem can only be solved, by supposing that, two ova had been impregnated when this woman was conceived, one of which, in some manner, became imbedded within the other, so that at her birth this lady had within her abdomen the remains of her _undeveloped twin_. These became encapsulated within the pelvis, and finally induced the local disease, which resulted in death.