222 Chick Anti - Human Blood Group

Two contradictory hypotheses regarding the origin of anti-human blood group A and B aggiutiuins have been advanced. According to the genetical theory proposed by Bernstein (3), Furuhata (4), Hirszfeld (5), and by others, these agglutinin~ are in* herited by linked gene pairs, each representing a blood group antigen and its complementary antibody. Thomsen (6) considers anti-?, and anti-B agglutinins to be physiological products, the function of the blood group gene being specific inhibition of production of homologous antibody. Other authors notably Dupont (7), Armangu6 (8), Wiener (9), and Kabat (10), and in a quite general way Boivin, Corre, and Lehoult (11), contend that these antibodies result from contact with exogenous crossreactive and homologous antigens. They base their contention on the widespread distribution (12, 13) of blood group antigens and blood group cross-reactive substances in nature. Most sera from heterologous species contain species-specific antibodies which agglutinate all types of human erythrocytes (of. reference 10). Bailey (14) found agglutinins against the erythrocytes of numerous animals and man occurring in 16 to 30 day old chicks and thought that they were inherited. Specific "natural" anti-human blood group aggiutinins occur in many animals. In chicks they have apparently been observed first by Schiff and Adelsberger (15) and by Eisler and Howard (15). In more recent studies, they have been found regularly by Baer, Bringaze, and McNamee (17) and by Baer (18), who studied anti-human blood group A and H(O) agglutinins, by Iseki, Onuki, and Kashiwagi (19), who investigated anti-human blood group B agglutinins, and independently by us (2). In agreement with several authors (15, 20),