314 THE BLOOD. 



to FREUND 1 it is this adhesion between the blood and a foreign substance 

 and the diseased walls of the vessel also act as as such that gives the 

 impulse toward coagulation, while the lack of adhesion prevents the 

 blood from coagulating. BORDET and GENGOU 2 have also shown that 

 the plasma obtained by centrifuging blood collected in a paraffined 

 vessel, and perfectly free from form-elements, can be kept without coagulat- 

 ing in a paraffined vessel, and that it does coagulate on being transferred 

 to an unparaffined vessel. The adhesion of the plasma to a foreign 

 body may also, in the absence of form-elements, give the impulse to 

 coagulation. That this adhesion of the form-elements is of great impor- 

 tance cannot be denied and is also generally accepted. By this adhesion 

 the form-elements undergo certain changes which seem to stand in a 

 certain relation to the coagulation of the blood. 



The views in regard to these changes are, unfortunately, very diver- 

 gent. According to ALEX. SCHMIDT 3 and the Dorpat school an abun- 

 dant destruction of the leucocytes, especially polynuclear leucocytes, 

 takes place in coagulation, and important constituents for the coagula- 

 tion of the fibrin pass into the plasma. A direct relation between the 

 destruction of leucocytes and coagulation is denied by many investigators, 

 while according to other experimenters the essential factor is not a 

 destruction of the leucocytes, but an elimination of constituents from 

 the cells into the plasma. This process is called plasmoschisis by LowiT. 4 

 The passage of cell constituents into the plasma before coagulation must 

 not necessarily be considered as a phenomenon of death, as it may just 

 as well be a secretory process (ARTHUS, MORAWITZ, DASTRE 5 ). 



Great importance has also been ascribed to the blood-plates in coagula- 

 tion as certain investigators (BIZZERO, LILIENFELD, SCHWALBE, MORA- 

 WITZ, BURKER, DEETJEN, LE SOURD and PAGNIEZ) found that they 

 induce, accelerate or make coagulation possible. According to VINCI and 

 CHISTONI they are not necessary as they are absent in the blood of 

 birds, which coagulates rapidly, and also in the lymph, of the dog, rabbit 

 and cat. They may nevertheless accelerate coagulation and they are 

 necessary for the contraction of the clot. According to AYNAUD they 



1 Freund, Wien. med. Jahrb., 1886; Haycraft and Carlier, Journ. of Anat. and 

 Physiol., 22. 



2 Annal. de 1' Institute Pasteur, 17. 



3 Pfluger's Arch./ 11. The works of Alex. Schmidt are found in Arch. f. Anat. 

 und Physiol., 1861, 1862; Pfluger's Arch., 6, 9, 11, 13. See especially Alex. Schmidt, 

 Zur Blutlehre (Leipzig, 1892), which also gives the work of his pupils, and Weitere 

 Beitrage zur Blutlehre, 1895. 



4 Wien. Sitzungsber., 89 and 90, and Prager med. Wochenschr., 1889, referred 

 to in Centralbl. f. d. med. Wissensch., 28, 265. 



6 Morawitz, Hofmeister's Beitrage, 5; Arthus, Compt. rend. soc. biolog., 55; 

 Dastre, ibid., 55. 



