332 Veterinary Medicine. 



flanimation by reason of the friction of the blood when violently 

 forced through the narrow opening in excited conditions of the 

 heart, by the strain thrown upon them from the violent contrac- 

 tions of the heart or the recoil of blood in the arteries, and by 

 their susceptibility in common with all other fibrous structures to 

 rheumatic inflammation. The redness is of the ramified or 

 branching kind characteristic of inflammation, and is neither re- 

 movable by washing the surface nor does it correspond in position 

 with the colored portion only of a clot which the cavity in ques- 

 tion may contain, as seen in bloodstaining occurring after death. 

 There is further exudation of plastic lymph into and beneath 

 the serous membrane, rendering it opaque, white and thick, or on 

 its surface forming granular elevations, and in the case of the 

 valves becoming moulded into ridges or festoons by the mutual 

 pressure of the different flaps on each other. The inflamed sur- 

 faces are further liable to be covered by masses of blood clot in 

 successive layers, deposited by the action of the fibrinogenous 

 matter developed in the inflamed part. These clots sometimes 

 accumulate in considerable masses, firmly adherent to the heart's 

 walls or valves by their attached surface, but soft and filamen- 

 tous on their free aspect. These clots or pol}'pi, as they have 

 been called, are soft and loose on their free surface, and become 

 firmer toward their points of attachment. In other words their 

 consistency is in direct ratio to their age. If of old standing they 

 are usually pale yellow or white and streaked with red, while if 

 recent they are mostly red throughout. They vary in size from 

 a thin film to a mass filling up nearly the entire cavity in which 

 they are lodged, and as they frequently extend through the auri- 

 culo-ventricular openings or become applied against this or the 

 opening of the great artery, they seriously and sometimes fatally 

 interfere with the circulation. Leblanc asserts that large masses 

 of this kind may be deposited in a few days. or even hours, caus- 

 ing sudden deaths, and especially in dogs. He has found other 

 circumstances than endocarditis to cause these fibrinous deposits, 

 and especially the absorption of pus, or the sudden suppression 

 of a long standing discharge, as in catarrh of the air-passages. 

 If death does not immediately ensue, these fibrinous deposits may 

 become vascular, as is the case with false membranes in the 

 the pleurse, becoming organized into fibrous tissue, or even de- 



