The general situation concerning scarlet fever in the United States in recent years is in the nature of a lull after the storm. Efforts now seem to be turned principally toward applying the American theories of the streptococcal origin of the disease to its prevention and cure. In Germany and France the subject has been under active controversy since the scarlet fever congress was opened in Konigsberg in 1928 and in Paris in 1930. As Streptococcus scarlatinae seems to have no specificity distinguishing it from other types, certain investigators have sought something other than the streptococcus as the activator (Zlatogoroff, Mandelbaum and Cantacuzene). On the basis of the Italian and American theories offered since 1924, we have conducted researches for five years concerning the problem of scarlet fever, and as a result we have solved several questions. 1 The Italian theory seems to retain only a slight influence, and present