According to my observation, when a fungous or warty excrescence has grown from the ruptured edges of the membrane, it has been from them exclusively, and from no other part of the lining of the same heart. And as rupture of the membrane seldom occurs in more than one situation at a time, the heart of the same individual seldom presents more than one excrescence of this kind: and as the aortic valves are the parts most liable to rupture, it is there that this single excrescence is most frequently found; not that rupture may not take place elsewhere. I once saw a single _chorda tendinea_ ruptured; and a single fungous excrescence of considerable size hanging from it into the cavity of the left ventricle. Now, this morbid growth is evidently connected with the lacerated state of the membrane in the conditions of its production, whereby it is limited to a small space. It is probable that the membrane is first ruptured; that its lacerated edges inflame, and then throw out unhealthy lymph, or unhealthy granulations, in the shape of these fungous or wart-like excrescences. When they have sprung from a ruptured membrane, they have, in the specimens which I have examined, been larger than when they have arisen under other conditions. But when such excrescences grow from the surface of the membrane which is thickened and cartilaginous only, but not lacerated, they are more apt to occur in many parts of it at the same time. I have seen the valvular apparatus between the auricles and ventricles on both sides, as well as the aortic valves of the same heart, studded with them. They were all about the size of hemp seeds: they adhered to the membrane with different degrees of tenacity, and wherever they were capable of being detached, they left a rough surface. The lining of the arteries has been known to give origin to morbid growths of the same kind, which have obstructed the passage of blood, and given occasion to the formation of a coagulum, which has obliterated the pulse. The internal lining of the heart is liable to ulceration, not as a common consequence of simple inflammation, but as an occasional consequence of some of those diseased conditions which have been described. It is most commonly found around scales and spiculæ of bone, and under such circumstances as to leave no doubt that the bone itself has furnished the source of irritation from which it springs. The ulceration commences from the very border of the bony scale, as if it was a process of nature for detaching it, and to a considerable distance around the ulceration the membrane is reddened, and easily detached from the subjacent structure. Where there are several distinct scales of bone, it is not uncommon to find a circle of ulceration around each of them.