This condition of the heart, may involve the whole organ, or may be confined to one or more portions. It is much less common in the auricles, than in the ventricles, and more frequent in the left ventricle than in the right. It will be generally found more advanced in the upper portion of the septum of the ventricles, and in the large, fleshy columns of the left side; or it may be found in these columns alone, which accounts for the occasional rupture of the latter. _Fatty Degeneration_ may be associated with _fatty growth_, or with hypertrophy, or thinning and dilatation, and may be the cause of rupture. The general character of softness, paleness, and mottled color, should lead to _suspicion_ of the existence of this disease, when a microscopic examination being resorted to, the conclusion would be decisive. A small portion of fibre, examined with a power of 300 or 400 diameters, will present, in fatty degeneration, instead of the striated appearance of the normal fibre, a granular appearance, with numerous minute oil globules scattered through the fibre. In the palest part of the heart, the disease will be generally most advanced; but even here, the microscope will show some fibres in a healthy condition, while others around them are rendered completely granular. Exhausting diseases of various kinds, typhus and other severe fevers, phosphorus poisoning, etc., may result in this peculiar condition of the heart. 5. Morbid Growths. Under this head may be placed _tumors_, _cancers_, _melanosis_, and _hydatids_. =Tumors= of various kinds are occasionally found in connection with the heart. _Fibrous_ tumors of a small size may develop within the muscular walls, while _syphilitic_ growths, _cysts_, and _tubercular_ deposits may also, in rare cases, be discovered. =Cancer.= Cancer of the heart has been noticed in two forms—_epithelial_ and _medullary_. A man, fifty-eight years old, had an epithelial cancer of the eye, which was removed. Two years after, the man died with a large cancerous tumor over the parotid gland. A post-mortem examination revealed a cancerous mass, about an inch and a-half in diameter, imbedded in the apex of the right ventricle and septum of the heart. A microscopic examination revealed its epithelial character.[10] _Medullary_ cancer of the heart has been usually found associated with the same disease in the lungs and liver, and forms an investing mass which may involve the whole organ. =Melanosis= of the heart presents the same character as in other parts of the body, and is considered but a variety of the medullary cancer, pigmentary matter being added. It may be developed upon the surface, or may infiltrate the substance of the whole organ.