Histochemical changes in the pearl millet seeds soaked in 2 percent Sg toxin and in the leaves seedlings of raised from treated seeds were studied. No noticeable changes occurred in the embryo and endosperm in the seed at the time of germination. However, the number of polysaccharide granules increased during the initial symptoms (stage I) in the bundle sheath cells of leaves. Subsequently at stage II, the number of PAS positive granules decreased and disappeared at stage III. The proteinoplasts Were less stained at stage I, which gradually disintegrated and ultimately disappeared. From stage I to III symptom development nucleic acids gradually decrease