70 STUDIES IN ADVANCED PHYSIOLOGY. 



and the clot seems in every way a typical normal blood clot. 

 If, however, some fibrinoplastiu had also been added, the 

 clot would have formed a little more quickly, but the final 

 product would not have differed from the first in any notice- 

 able way. 



The question naturally arises why blood does not coagu- 

 ' late in the body? If a blood vessel be removed from the 

 body and the ends tied, the blood will not clot for hours. 

 In fact, it is possible to cut out a turtle's heart and have 

 the blood remain liquid in it for seven or eight days, and 

 yet such blood when exposed in many other ways begins to 

 clot at once. Some have tried to ascribe to the lining of 

 healthy blood vessels a sort of inhibitory function, but this 

 is a mere explanation of words and not of ideas. The point 

 remains that for some yet unexplained reason the fibrin 

 ferment does not seem to have been produced, possibly 

 because the blood plates and corpuscles have not been dis- 

 integrated in a way calculated to produce this ferment. 

 Such abnormal conditions as a bruised blood vessel, expos- 

 ure to the air, contact with foreign bodies, serve to disinte- 

 grate them and so start the process of coagulation. 



While in the discussion so far the formation of the fibrin 

 ferment has been attributed to the blood plates, there is 

 little doubt but that the white corpuscles as well, in their 

 disintegration, form this fibrin ferment. This may explain 

 why in certain diseases of the body in which corpuscles 

 disintegrate in large numbers internal clots have been 

 formed, interrupting the circulatory course and so causing 

 death. It is not an infrequent observation too that in per- 

 sons suffering from blood poisoning, a disease in which 

 large quantities of corpiiscles are lost, there is a tendency 

 towards the formation of internal clots, which frequently 

 prove fatal before the full effects of the blood poisoning have 

 had time to arrive. In fact, in fevers generally the amount 

 of fibrin ferment in the blood seems a little more abundant. 

 While in the daily life of a healthy individual many such cor- 

 puscles disintegrate, they do not do so in sufficient numbers 



