The histology, fine structure and histochemistry of the digestive gland of Lymnaea stagnalis was examined before and after treatment with a crude water extract of a powerful molluscicidal plant, Detarium microcarpum. The results obtained indicate that the molluscicidal extract induces necrosis in the digestive gland typified optically by cellular oedaema and nuclear pyknosis. At electron microscope level molluscicide treatment is seen to induce a major vacuolation and fragmentation of the cytoplasm. Lysosomal acid phosphatase and lysosomal integrity however is preserved. Histochemically, both acid and alkaline phosphatase appear to survive treatment very well. In treated tissues there is a shift of alkaline phosphatase from the brush border to the lumen. Molluscicide treatment results in a distinct inhibition of ATPase activity which appears to be a characteristic feature of induced cell death.