THROMBOSIS. 



227 



liow do matters stand with regard to the intercellular substance 

 of this very peculiar connective tissue ? 



The red corpuscles together with the fibrin make up the bulk 

 of the recent thrombus. Hence it is to alterations in therrij that 

 such changes in the clot as we are able to trace with the naked 

 eye, must be chiefly due. The rapid escape of colouring matter 

 from the red corpuscles explains the decolorisation of the clot ; 



Fig. 72. 



Longitudinal section througb. the ligatured end of the crural 

 artery in a dog, fifty days after operation. Injected by 0. 

 Weher. Tli. Thrombus. M L Middle coat; Z. Areolar 

 coat. 



its shrinking and increased dryness are due to the contraction of 

 the fibrin and the consequent expulsion of the contained fluid. 

 What remains therefore is — 1st, instead of every red corpuscle, a 

 flake of colom-less protoplasm ; 2nd, the fibrin as an invisible 

 but nevertheless very firm cement which binds these flakes 

 together. The two form a mass which is not easily torn 

 and which is never fibrous ; from the first until about the 



