CIRCULAR lUSTUKllANCES. 



125 



blood cells are entangled. A white thrombus consists essentially of 

 a mass of fibrin in which an occasional leucocyte or |)latelet 

 may he found. 



Secondary Changes of Thrombi.— 1. Dccolorbation. A red 

 thr.inibus may become decolorized as a result of de,;;-enerative 

 changes in the red bloods cells. The contained liemoolubin be- 



-.\ Thrrinibus from the pnsti'tmi aoita ot a htnsH ils i a si- 

 jisttrior \'<-na cava uL' a cl'W cuntaming a thi<.tmT)US, 



ing lil:)erated mav in [lart lie cnnx-erted intt) otlier pigments and 

 in part ma^• be carried away l)y in\'ading leucoc}tes. 



Softening. Thrombi, either red or white, are somctinu's 

 degenerated, di.'integrated, absorbed and carried awa\- as a 

 result of the following: 



(A) Simple softening is a noninfective, degeneratix'c pro- 

 cess that l^egins in the center (if the throml:)ic mass and con- 

 sists of albuminous, granular or fatty degeneration. The spe- 

 cific cause of the degeneration is not known but is no (loul)t 

 the result of ferments. The degeneration extends from the 

 center until the entire thrombus is involved. The disinte- 



