The palatine tonsil is thought to be the organ which accepts antigens to initiate an immunological response, but the incorporation of the antigens from the oral cavity was not yet known. To show this incorporation, fluorescence-labeled Candida albicans and a lipopolysaccharide were instilled around the rabbit palatine tonsil. The distribution of fluorescence was examined in frozen sections of the tonsil after 30 , 60 and 180 minutes of the instillation. Candida albicans and a lipopolysaccharide were incorporated into the cryptoepitherial tissue of the palatine tonsil within 30 minutes. The antigens in the epithelium were transported to the intratonsillar follicles and partly to the deep cervical lymph nodes after 60 minutes. The lipopolysaccharide was found intrafollicular by in both the tonsil and the deep cervical lymph nodes earlier than Candida albicans was. Because the normal cryptoepithelium easily passed through the external antigens which were transported to the neighboring lymphoid follicles, it was suggested that the cryptoepithelium was the entrance of the immunological response in the palatine tonsil and neighboring lymphoid tissues in the normal condition.