Soluble antigens of Trypanosoma vivax and of other trypanosomes.

Precipitins against trypanosomal antigens occurred in serum from Zebu cattle which had been infected for prolonged periods with transmitted by . Precipitating antisera against were used to detect complexes of soluble trypanosomal antigens in sera from rats infected with blood-passaged strains of and and in sera from goats infected with a cyclically transmitted strain of . The immunological relationships of antigens of these three species of trypanosomes were studied in terms of antisera against . It was found that the antisera contained antibodies which reacted with antigens common to the three species of trypanosomes. The antisera also contained antibodies which reacted with antigens which may be specific to .