The Size And The Metamorphosis Of The Vegetations afford evidence of the intensity of the endocarditis, and more especially of the quality of its products, when, besides these, other essential phenomena of endocarditis are present, and when the diseased condition of the blood can alone be referred to endocarditis.

In some rare cases where these vegetations are unaccompanied by any other important phenomena of endocarditis, they are usually inconsiderable in number and dimensions; and the question might arise, whether they may not even here originate in some very slight degree of endocarditis, which might produce scarcely perceptible disturbances of texture, that had been masked and hidden by the presence of the vegetations. We must, however, bear in mind that the origin of these fibrinous coagula is, in general, mainly dependent on some peculiar character in the blood, that it admits not unfrequently of being referred to some process remote from the heart, and that in some cases even it may be said to be spontaneously developed; that in addition to benignant and inconsiderable vegetations, there are other extensively diffused secondary processes in the different parenchymatous structures, which have a wholly heterogeneous character, and terminate in purulent fusion; that there is no trace of endocarditis to be detected, or, at all events, no new endocarditis corresponding to the recent condition of the vegetations; that a mechanical influence is especially important in the deposition of these vegetations which are formed not only on every rough part of the endocardium and the valves, but even on the lining membrane of the vascular trunks; and lastly, that the normal valvular apparatus, by means of its tendons, affords a highly favoring requirement for the separation of the fibrin. The above observations leave no doubt that, like other fibrinous coagula, these vegetations may be formed and deposited independently of simultaneous endocarditis, and in consequence of some other disease of the blood, upon any favorable portion of the inner surface of the heart, as, for instance, the free margin of the valves, which has become suited to its reception by incidental roughness or inequality of surface.

These vegetations cannot, therefore, be regarded as constituting an absolute indication of endocarditis, whose existence requires to be confirmed by the presence of more essential disturbances of texture, but must be considered simply as evidences of a diseased condition of the blood. If, however, such disturbances are present, these vegetations enable us, in the manner already described, to form an opinion in reference to the intensity of the endocarditic process, and the nature of its products.