By homografting of skin on the dorsum of the left ear of adult rabbits, the effects of complete Freund's adjuvant on the response of the regional lymph node have been studied. The essential results obtained are as follows:
1) The proliferative response of the regional lymph node to skin homografts is markedly increased by a single intraperitoneal injection of complete Freund's ajuvant, whereas the skin homograft survival is not shortened at all.
2) The results indicate that in transplantation immunity the nonspecific proliferative response of the regional lymph node elicited by complete Freund's adjuvant is not converted into the specific one which ultimately leads to the formation of antibody.