Endocarditic Hypertrophy, like that of the aorta and its ramifications, especially occurs in advanced periods of life, and undoubtedly constitutes the source from whence arise a great number of those diseases of the aortic valves, - as, for instance, thickening, shrivelling, ossification, and insufficiency, - which are slowly developed in maturity and old age, without the pre-existence of endocarditis. This fact presents many points of great interest, when considered in relation to diseases of the mitral valves, which usually occur in young persons as a result of well-marked endocarditis.

This affection is frequently occasioned and favored by pre-existing dilatation of the heart and contraction of the openings, in consequence of which the blood is detained in the different cavities, and its further circulation impeded.

Atrophy or Attenuation of the Lining Membrane of the Heart is very seldom sufficiently manifested to come under notice. This membrane is certainly found to be uncommonly thin and transparent in some cases of dilatation of the heart; while we have remarked the same appearance in excessively fat hearts.