We are continuing our studies of the diversity and specialization of antibody-forming cells with the objective of gaining understanding of the induction and control of antibody formation. This coming year we propose to: Complete a study of the quantitative relationship between anti-arsanilazo (anti-AA) hemolytic activity and molecules of anti-AA antibody. Measure the relative binding strength for AA-hapten of the anti-AA antibodies from homozygous a1 and a3 rabbits. Study serum trimethylammonio para phenylazo antibodies in a1,3 rabbits to clarify the shift from almost entirely allotype a3 in the primary PFC response to a balance between a1 and a3 when judged by enhancement of secondary PFC. Study the distribution of allotypes in the a1,3 offspring of homozygous a3 rabbits descended from a1,3 parents in which anti-AA was almost entirely of allotype a1 globulin compared to those on which it was evenly balanced between a1 and a3. BIBLIOGRAPHIC REFERENCE: Chau-Chun Chien and J.S. Ingraham, "Preferential assignment of allotype a1 globulins for the production of antibodies against acidic aromatic azohaptens in a1,a3 rabbits." Fed. Proc. 35, 630 (1976) (ABSTRACT).