RELATIONS OF THE RED BLOOD-CORPUSCLES. 71 



death may take place in consequence of widespread coagulation. If the animal 

 survive immediate death by reason of the moderate extent of coagulation, the 

 blood subsequently will be wholly incoagulable in consequence of the absence of 

 leukocytes. 



All protoplasmic structures may in combination with plasma set the 

 fibrin-ferment free. The nitrogenous metabolic products of proteids 

 are likewise capable of producing fibrin-ferment in plasma free 

 from cells. These latter active substances can be extracted from the 

 tissues cells of the liver, the spleen, the lymph-glands, red and white 

 blood-corpuscles, frog-muscle by means of alcohol. If after alcoholic 

 extraction the residue of such tissues is extracted with water, this 

 watery extract absolutely inhibits coagulation. The substance thus 

 extracted by water is designated by Alex. Schmidt cytoglobin, which is 

 the forerunner of fibrinogen and also of serum-globulin. 



In accordance with the preponderance in the plasma of either of 

 the substances capable of extraction with alcohol or cytoglobin, coagu- 

 lation is induced or inhibited respectively. Within the living body the 

 inhibitory action of the cells preponderates, while outside the body 

 the coagulating effect is operative. Those substances, such as the 

 cytoglobin, that inhibit coagulation within the circulation furnish out- 

 side of the body the material for the formation of fibrin. As Alex. 

 Schmidt, after addition of cytoglobin to filtered plasma, induced coagu- 

 lation by addition of extractives in large amount, the amount of fibrin 

 was more than doubled. The blood retains its fluidity in the circulation 

 as long as the amount of cytoglobin exceeds that of the proteid metabolic 

 products of the tissues. The blood may, however, remain fluid also 

 because both of these do not pass over into the plasma. 



Pathological. From the investigations of Alex. Schmidt in collaboration with 

 his pupils Jakowicki and Birk, it has been shown that even healthy functionating 

 blood contains some fibrin-ferment from the destruction of white blood-corpuscles 

 normally undergoing dissolution, and in greater amount in venous than in arterial 

 blood. Nevertheless, it is always more abundant in shed blood. The fact, how- 

 ever, is particularly noteworthy that the amount of fibrin-ferment in the blood 

 in cases of septic fever may increase to such a degree that spontaneous coagulation- 

 thrombosis takes place and even terminates fatally. After injection of putrid 

 matters leukocytes are dissolved in large number, but the ferment is present rather 

 abundantly also in the blood of febrile patients generally. Also injection of pep- 

 tone, of hemoglobin and in lesser degree of distilled water is followed by dissolution 

 of numerous leukocytes. There are thus true blood-diseases in which the products 

 of the dissolution of the leukocytes accumulate in the blood-plasma. In conse- 

 quence, spontaneous coagulation naturally occurs within the circulatory organs, and 

 as a result death may even be brought about. At least febrile elevation of tempera- 

 ture usually takes place. At the termination of such conditions the coagulability 

 of the blood is naturally diminished. 



Wooldridge showed that a fibrinogen tissue- fibrinogen occurs in the chyle and 

 in the lymph as a product of the lymphatic glands. In human beings in whom 

 blood-stasis exists in any part of the body, coagulation may take place, with 

 the formation of thrombi, through admixture of lymph, as a certain amount of 

 ferment is already present in the blood. The intestinal mucosa, the skin, and the 

 lungs also appear to produce small amounts of fibrinogen constantly, while the 

 liver and the kidneys constantly destroy it. 



RELATIONS OF THE RED BLOOD-CORPUSCLES TO FIBRIN- 

 FORMATION. 



After it had been determined by a number of investigators that also 

 the erythrocytes of birds, of the horse, of the frog, may contribute to the 



