THE REGENERATION OF F1 HOST CELL SPLEEN AND THYMUS AT ECTOPIC SITES IN F1 ANIMALS INDUCED BY IMPLANTATION OF PARENTAL SPLEEN AND THYMUS

The ability of parental to F1 spleen grafts to regenerate was equal to that of parental to parental or to F1 or F1 spleen grafts. Cytotoxicity analysis of parental to F1 spleen and thymic grafts indicated that these "regenerated grafts" were composed of F1 lymphocytes. Regenerated parental to F1 spleen grafts were incapable of producing runt disease in newborn F1 animals