Acid phosphatase, five-nucleotidase, ATPase, aminopeptidase, alkaline phosphatase and non-specific esterase activities were demonstrated in the schistosomal ova in the livers of mice experimentally infected with Schistosoma mansoni. In addition, the ovum contained a complex carbohydrate which is probably its main antigenic component. Granulomatous tissue around the ova displayed histochemical reactions characteristic of chronic proliferative inflammation. The reticuloendothelial cells in liver and spleen exhibited high acid phosphatase activity.
Foreign Research Fellow, U.S.P.H.S., at the Department of Pathology, The Mount Sinai Hospital, New York. Present address: Hospital das Clinicas, Salvador, Bahia-Brazil.