Parenteral injections of scarlatinal streptococcus filtrate toxin either subcutaneously or intramuscularly are followed in a short time by a loss of skin sensitivity to the toxin. Peters and Allison, 1 by spraying a solution of the toxin every second day for five weeks on the nasal mucosa, reported that of sixty-one children so treated, negative reactions to the Dick test developed in twenty-two and in twenty-four others the skin reaction was "much reduced" at the end of this period. In the present paper are reported the results of a series of experiments in which the toxin was administered in various ways through the gastrointestinal tract and the effect on skin sensitivity observed. MATERIALS AND METHODS The children studied were patients at the Shriner's Hospital for Crippled Children who were undergoing orthopedic treatment, and who were apparently free from infections. Skin tests were made with standard toxin from the United States