THE CIRCULATORY SYSTEM. 447 



cavities of the heart, and disturbances of the circulation throughout" the 

 body. 



4. Chronic Ulcerative Endocarditis. Large ulcers or perforations of 

 the valves may be formed in chronic endocarditis, upon which clots 

 may form, so that in gross appearance a great similarity exists between 

 this and malignant ulcerative endocarditis, particularly if the latter 

 have been engrafted upon an already chronically diseased endocardium. 

 The microscopical and biological examinations must usually be resorted 

 to in order to determine the exact significance of the lesion. 



5. Tuberculous Endocarditis may occur in connection with tuberculous 

 pericarditis or general niiliary tuberculosis. The tubercles may be small 

 and single, or grouped in masses, and show the usual degenerative 

 changes. ' 



TUMORS. 



Primary tumors in the heart are rare, but sarcomata, myxomata. 

 fibromata, and lipomata may occur. Rhabdomyomata. probably con- 

 genital, may occur in the heart wall as circumscribed nodular masses." 

 A cavernous tumor of this kind has been described. Secondary tumors, 

 as a result of metastasis or of continuous growth from the pleura or other 

 adjacent parts, are not very infrequent. These are usually carcinomata 

 or sarcomata. Secondary chondromata have been observed. 3 



PARASITES. 



Echinococcus sometimes occurs in the heart wall and may perforate 

 into the cavities. Cysticercus cellulosae has been observed. 



The Blood-Vessels. 



ATROPHY AND HYPERTROPHY. 



Atrophy of the blood-vessels may involve the entire trunk or some of 

 its elements. It may occur as a part of general malnutrition of the body, 

 or in connection with atrophy of particular organs, or as an accompani- 

 ment of various diseases of the vessels themselves. 



Hypertrophy, which is especially seen in the arteries, may occur in the 

 establishment of a collateral circulation upon the closure of arterial 

 trunks; or it may occur as the result of increased blood pressure, as in 

 some forms of hypertrophy of the heart. 



'See reference, Moser, p. 406. Also fitienm, Arch, de Med. Exp., vol. x., p. 146, 

 1898. 



*Seiffert, Ziegler's Beitr., Bd. xxvii., p. 145, 1900, bibliography. 



3 For bibliography of heart tumors consult Berttienson, Arch, de Med. Exp., vol. v., 

 p. 386. 



