468 DISEASES OF THE CIBOULATORY SYSTEM. 



in the rabbit on the subject of the etiology of ulcerous endocarditis. 

 By tearing the valves of the heart and injecting into the veins the 

 Streptococcus pyogenes he has produced phenomena similar to those 

 of ulcerous endocarditis (mycotic) of man. His experiments have 

 proved that the slightest wound of the valves is sufficient to per- 

 mit micro-organisms, which are inoffensive in the uninjured circu- 

 latory apparatus, to produce a fatal endocarditis. The Staphylococcus 

 pyogenes aureus and cocci of septicemia have given similar results.^ 

 Pathological anatomy. The macroscopic alterations vary with 

 the cause and degree of intensity of the disease. In the benign 

 rheumatismal forms the loose edges of the valves, the chordae ten- 

 dinese and the papillary muscles are covered with miliary prom- 

 inences, which are of a grayish or yellowish-white color, and similar 

 to granulations or small pimples. When these neoformations exist 

 in large numbers the serous membrane is coated with a layer of 

 pustules which give to it a glandulous or warty aspect ; they are 

 often covered with a fibrinous, stratified, bloody, or discolored exu- 

 date (warty endocarditis). If developed on the loose edge of the 

 valves they may be transformed into enormous polypous vegeta- 

 tions which determine the insufficiency of the valves or the contrac- 

 tion of the orifices. In cases where the granulations are of very 

 small dimensions the endocardium seems slightly rugous ; it is 

 tumefied, turbid, red, and covered with an exudate. The sub- 

 endocardial connective tissue, also the epicardial and interstitial, 

 are overrun with small hemorrhagic centres. In the serous septic 

 forms we observe small mortified spots and ulcerations upon the 

 serous membrane (ulcerous endocarditis). These latter are ordi- 

 narily superficial, their dimensions varying from the size of a 

 lentil to that of a twenty-five- cent piece ; they are covered with a 

 dirty, spongy, friable necrotic exudate, which may be dragged away 

 by the blood-current into almost any organ. Purulent embolus of 



1 In making a culture of the blood obtained from a woman who had died of malig- 

 nant endocarditis caused by an ulceration of the upper lip, Gilbert and Lion have 

 been able to isolate and cultivate a microbe which seemed to play an important rôle 

 in the development of this cardiopathy. The inoculation of a few drops of the cul- 

 ture of this micro-organism in some rabbits, which were free from any previous val- 

 vular traumatism, has produced a vegetating endocarditis in these animals, which 

 was with or without aortitis, and the lesions of which were absolutely identical with 

 those which determine this disease in man. The microbe was found in the vege- 

 tations of the mitral and tricuspid valves. (Bull, de la Soc. de Biologie, 1888-90.) 



