The long-term distribution of antibody-forming cells

Previous experiments suggested that the spleen might not be the chief source of serum antibody synthesized several months after the immunization of mice by sheep erythrocytes; this has been confirmed for classes other than γM. The anatomical location of the cells making the antibody is not the same for each class. The thymus contains a relatively greater number of non-γM antibody-producing cells late in the response than it does in the first three weeks after immunization.