“…It is a moot point whether the findings here are similar to those of Hellstrom et al (1971) except that at some stage in the proceedings both methods induce tolerance by massive doses of cellular aUoantigen. Zaleski et al (1971) studied the kinetics of emergence of antibody forming cells in allogeneic parent-parent and parent-hybrid pairs and showed that antibodies to & antigens and H-2 antigens were exchanged between the partners. A plaque forming cell (PFC) technique was used.…”