CAPILLARY EMBOLIA. 



243 



sent the same results, but are still less dependent upon 

 an original phlebitis. Thus, for example, endocarditis 

 by no means seldom forms the starting point of such me- 

 tastases. Ulceration takes place in one of the valves of 

 the heart, not by means of the formation of pus, but in 

 consequence of an acute or chronic softening ; crumbling 

 fragments of the surface of the valve are borne away by 

 the stream of blood and reach with it far distant points. 

 The kind of obstruction which these masses produce is 

 altogether similar to that which the thrombi in the veins 

 give rise to, but they present a different chemical consti- 

 tution. Their minuteness also and their friability favour 

 their penetration into the smallest vessels in a high de- 

 gree. Therefore we do not so very unfrequently find 

 the obstructing mass in minute microscopical vessels 



FIG. 74. 



FIG. 76. 



Fig. 7475. Capillary embolia in the tufts (penicilli) of the splenic artery after 

 endocarditis (Of. Gesainmelte Abhandlungen zur wiss. Medicin. 1856, p. 716). 

 74. Vessels of a tuft magnified 10 times, in order to show the position of the oc- 

 cluding emboli in the arterial district. 75. An artery filled a little before its divi- 

 sion, and in the branches into which it next divides, with fragments of the finely 

 granular embolic mass (Of. Fig. 73, c). 800 diameters. 



