(n.) An albuminous body, insoluble in water, but soluble in dilute solutions of salt. It is present in the red blood corpuscles united with haematin to form hemoglobin. It is also found in the crystalline lens of the eye, and in blood serum, and is sometimes called crystallin. In the plural the word is applied to a group of proteid substances such as vitellin, myosin, fibrinogen, etc., all insoluble in water, but soluble in dilute salt solutions.

Rh factor Rh-negative Rh-positive Rh-type Rhesus factor acquired immunity active immunity agglutinin allergen anaphylactin antiantibody antigen antiserum antitoxic serum antitoxin antivenin arterial blood artificial immunity blood blood bank blood cell blood count blood donor blood donor center blood group blood grouping blood picture blood platelet blood pressure blood serum blood substitute bloodmobile bloodstream circulation clinical dextran congenital immunity dextran erythrocyte familial immunity globulin gore grume hematics hematologist hematology hematoscope hematoscopy hemocyte hemoglobin hemometer humor ichor immunity immunization incomplete antibody inherent immunity inherited immunity interferon isoantibody leukocyte lifeblood natural immunity neutrophil nonspecific immunity nonsusceptibility to disease opsonic immunity opsonin passive immunity phagocyte phagocytic immunity plasma plasma substitute precipitin racial immunity red corpuscle resistance serum specific immunity toxin-antitoxin immunity type O venous blood white corpuscle