The man who recognized the spirochetolysis of pathogenic tissue spirochetes was probably only Bergel. He reported that the lipolytic ferment excreted from lymphatic cells may cause the spirochetolysis destroying the lipoid membrane of the spirochetes, and this plays the main role in the protective function of living body against syphilitic infection. But he did not mention whether or not this enzyme corresponds to the immunologically specific spirochetolysin. At any rate, the immunological significance of the spirochetolysis of pathogenic tissue spirochetes is an undeveloped field.