Abstract
Sections of adult Schistosoma mansoni and of infected mouse liver were incubated with antiserum monospecific for the antigen found in the circulation of schistosome-infected animals. By indirect immunofluorescence, antigen was found only in epithelial cells of the gut and the border of these cells with the lumen. This corresponded to an area of diastase-fast PAS-positive staining, which is consistent with previous data indicating that this antigen was a polysaccharide. The antigen was not found elsewhere in the worms or in the liver of infected mice.