SUMMARY: The present studies have shown that some epithelial elements of donor origin survive the homograft response and that, provided adequate physical protection, particularly against desiccation, is given to the graft, these elements may regenerate.Regeneration of follicular epithelium was invariably observed as early as 8 to 10 days after homotransplantation of skin in specifically presensitized mice. Regeneration of both follicular and surface epithelial elements is usually completed by about the 16th day after grafting in these animals. By comparison, epithelial regeneration was delayed, and was observed much less frequently in homografts transferred to non‐immune recipients.Inhibition of the regenerative capacity of the donor tissues by X‐irradiation before transplantation prevented or grossly delayed regeneration of both follicular and surface epithelia in the graft area.An immunological test based upon Mitchison's (1956) design was used to demonstrate the presence of antigens of both donor and host provenance in the regenerated tissues. The presence of donor elements was confirmed by showing that the transfer of appropriately presensitized and normal spleen cells of the recipient strain to X‐irradiated mice bearing the regenerated homografts resulted in destruction of the regenerated tissues.Homograft regeneration was promoted by passive administration of serum obtained from mice hyper‐immunized with donor‐type spleen cells. This finding suggested that an “enhancement” phenomenon might play an important rôle in the fate of the regenerating tissues.