On the Haemolytic Immune Isolysins of the Ox and their Relation to the Question of Individuality and Blood-relationship

The term “Isolysin” was first employed by Ehrlich and Morgenroth in the third of their now classical series of papers entitled “Studies on Haemolysis(1).” It had been shown by Bordet that if the red blood corpuscles of an animal A are injected into another animal B, of a different species, the serum of B develops a haemolysin for the corpuscles of A. This haemolysin being produced in a different species of animal from that yielding the corpuscles, is termed, according to Ehrlich's nomenclature, a heterolysin.