“…After the times shown in Table IX There was no decrease in the anticoagulant activity of the plasma following ether extraction. From this experiment it is concluded that the active principle of this anticoagulant is not a free lipid, nor it is a loosely bound lipid protein complex such as the antithrombin described by Gruning (14). The possibility remains, however, that The chemical behavior of the substance indicates that the activity is associated with a protein molecule, probably a globulin.…”