Recent Advances in the Problem of Blood Coagulation Applicable to Medicine

For a generation or more it has been accepted by most of the workers in this field that clotting of blood takes place in two steps: first, the formation of thrombin from prothrombin and, second, a reaction between thrombin and fibrinogen which leads to the deposition of fibrin needles and the gelatination of the blood. The factors entering into these reactions are expressed in the schema first used by Morawitz, as follows: prothrombin + Ca ions + thromboplastin = thrombin thrombin + fibrinogen = fibrin The schema is incomplete in that it fails to give the nature of the reactions in the two equations. On this point at present there is great diversity of opinion. It would be interesting to discuss the different views that have been proposed, but it would scarcely be profitable, since the weight of evidence at present does not incline to one view more than to another. Such a discussion, moreover,