The excrescence is generally of a dark colour, resembling a mass of coagulated blood, but of more soft consistence, and its extremity has often a sloughy appearance. It is evidently organised; for, on being injured even in a very slight degree, hemorrhage ensues from the part which has been broken or contused, and frequently the growth bleeds spontaneously. At first the hemorrhage is in general slight, but is often repeated, becomes very profuse, and in most instances cannot be arrested. The vessels in the substance of the morbid mass are diseased in their coats, and have altogether lost their power of contraction; they give way either spontaneously or by laceration, and by their non-contraction they appear to serve merely as passive tubes, through which the blood is poured out by the active vessels which supply them; the latter are not exposed to any of the causes which tend to produce speedy obstruction of their canals, therefore continue to transmit their contained fluid through their subservient branches, and from this the uncontrollable nature of the hemorrhage can be accounted for; from the number of vessels which supply the new structure, and which are thus employed, it can be readily imagined that the hemorrhage will be profuse. In many instances, the application of firm pressure on the limb above the seat of the disease is even insufficient to arrest the flow of blood; and though this may, in some degree, be explained by supposing the continued stream to be venous, still it must be confessed that the disease appears connected with a peculiar hemorrhagic tendency. Frequently the fungus is found to communicate with, or rather to arise from, numerous cysts of a glossy appearance, from which also blood is copiously effused. The surrounding tissues are completely disorganised in the immediate neighbourhood, and also much altered in structure for a considerable extent around; the muscles, besides their disorganisation, have acquired a peculiar brown hue. Sometimes the hemorrhage does not seem to proceed so much from the fungus as from the subjacent cysts; for when a superficial incision or puncture is made into it, the bleeding is often inconsiderable, and only becomes alarming after masses of coagulated blood have been removed, and the cysts thereby exposed. Occasionally the fungus communicates with a cavity of enormous size, filled with blood, partly coagulated and partly fluid, and from the parietes of which the hemorrhage proceeds. When the disease has supervened on a medullo-sarcomatous tumour, the coagulated blood is mixed with a substance resembling the brain in a state of putrescence. It may supervene on polypous tumours, particularly of the antrum; and of this I have seen several instances. Sometimes it is produced after the removal of a tumour apparently not of malignant character, and in this case it frequently does not appear till the wound has almost cicatrised. When once established, it proceeds with all its virulency.