1 - The above terms have, at different times, been applied to this class of concretions. We refer our readers to the general remarks on the diseases of the blood and its fibrin for all that relates to the pathology, nature, and metamorphosis of these structures. We purpose here treating specially of their form, and shall only touch upon their other relations as far as is necessary towards the right comprehension of a subject which has been much beset with errors in the present day.

1 Oesterr. med. Jahrbttcher, B. xxiv. St. 1.

The structures now under consideration occur in many forms. The question here arises as to these structures generally, and each form specially, whether they are produced after death or before it, and how long they had subsisted during life. It has long been customary to distinguish certain fibrinous coagula from others by the designation of death-polypi. The fact that the blood, in consequence of the arrest of the heart's action, coagulates more or less perfectly in the cavities, into a loose soft clot, or a more compact mass, from which the fibrin is more or less thoroughly separated into a concretion, which, in its turn, exhibits the most various degrees of consistence or plasticity, has long been regarded as entirely in unison with the phenomena observed in drawn blood that has been left to stand and cool. The symptoms presented in the course of disease, the peculiar character of the phenomena exhibited in the death-struggle, the form of certain fibrinous structures in the heart, their relation to its inner surface, and their adhesion to the endocardium, have long since been advanced in support of the view that there may exist, during life, an independent self-persistent polypus of the heart. This view has continued, to our own day, to be so entirely misunderstood and misapplied that even ordinary death-polypi have very commonly been mistaken for true polypi of the heart.

No doubt can be entertained in the present day that fibrinous concretions are formed in the heart from the blood during life. It would appear certain that they form an organic (textural) connection with the inner wall of the heart; and further, that they experience various metamorphoses in their elementary composition. We purpose considering these in the sequel; but we would, in the first place, make a few general remarks on the conditions under which fibrin is separated during life from the blood, and coagulates into different forms of concretion. We will also consider, under the head of these respective forms, all that relates to their formation after death or during life.

These conditions exist partly in the heart and partly in the blood, and both are not unfrequently coexistent: the latter, however, are the more important, while the former are to be regarded as merely affording favorable momenta.

1. The first condition involves an abnormally prolonged continuance of the blood in the cavities of the heart in consequence of a decrease in the activity of the heart's action, as in hypertrophies of considerable intensity, passive dilatations, aneurisms of the heart, and in every death-struggle depending on general paralysis, or in consequence of pre-existing contractions (stenoses) of the ostia; or, lastly, there may exist various mechanical conditions in the form of inequalities and roughness on the inner surface of the wall of the heart and on the valves, in its passage over which the blood deposits its fibrin in a corresponding form.

2. The other and most essential condition consists in the tendency of the blood to coagulate or to part with its fibrin in various forms of coagulation, either in consequence of spontaneous disease, or of the absorption in various ways, of some heterogeneous matter. Under this head we must especially class the so-called inflammatory (croupous) crasis, as it occurs in a primary or secondary form, associated with inflammations, pneumonia, rheumatism, etc.; the poisoning of the blood by the absorption of the multifarious products of the inflammation of normal or abnormal tissue, which have been produced within the vascular system on the endocardium, on the lining coat of the vessels, or externally to the vascular system, having in the latter case reached the blood by the most various channels.