"When the blood is poured out from its containing vessels into the substance or cells of the placenta, or between the membranes, gradually coagulates, and assumes a very dark purple, and sometimes almost a melanotic black colour: after a time, however, it begins to lose this tint, the colouring matter gradually becomes removed, and the coagulum successively assumes a chocolate brown, a reddish or brownish yellow hue; and latterly, if time sufficient be allowed, it presents a pale yellowish white or straw-coloured substance, the fibrinous portion of the coagulum being then left alone."[48] This form of mole, as far as our own observation goes, seldom attains any considerable size, rarely exceeding four inches in length, and is usually expelled between the eighth and twelfth week. The size and condition of the foetus varies a good deal; in some cases it appears nearly healthy, although the cord is much thickened and distended; this is probably owing to its having been expelled shortly after its death, or to its having gone on to live a short time after the injury which had caused hæmorrhage: in this way alone can we explain why we occasionally meet with cases where the parietes of the ovum are much thickened and solidified, and yet the embryo is in such a state of integrity as to prove that its death must have been very recent. The extravasation of blood between the ovum and uterus does not appear to be sufficient to annihilate immediately the nutrition of the embryo, so that the blood has had sufficient time to solidify before the ovum was expelled. At other times the embryo exhibits evident marks of having been dead some time: it is much smaller and younger in proportion to the size of the ovum; sometimes it has disappeared entirely, a short rudiment of the funis merely remaining to mark its previous existence. "Should the embryo die (suppose in the first or second month) some days before the ovum is discharged, it will sometimes be entirely dissolved, so that when the secundines are delivered, there is nothing to be seen. In the first month the embryo is so small and tender, that this dissolution will be performed in twelve hours; in the second month, two, three, or four days will suffice for this purpose." (_Smellie._) Where the growth of the ovum proceeds after the destruction of the embryo, it increases very rapidly in size, much more so than would be the case in natural pregnancy, so that the uterus, when filled with a mole of this sort, is as large at the third month as it would be in pregnancy at the fifth.