Figure 4: T.S of Biomphalaria alexandrina snails exposed to Schistosoma mansoni miracidia (SBSC): left panel (6hr post exposure), right panel (72hr post exposure). A&B: Ismailia snails, A: miracidium �Mi� (arrows) in head-foot region; note successful penetration of miracidia without tissue response at this time, B: hemocytes �H� infiltration around the abnormally developed sporocyst �Sp� in the head-foot region as an inward step of forming a capsule, C&D: Kafr El- Sheikh snails, C: three encapsulated miracidia �Mi� (arrows) in head-foot region; note obvious tissue reactions through hemocytes �H� aggregations around the miracidia, D: hemocytes �H� infiltration around the abnormally developed sporocysts �Sp� in the head-foot region forming a capsule, E&F: Damietta snails, E: two miracidia �Mi� (arrows) in tentacle; Note haemocytic response �H�, F: degraded sporocyst �Sp� and large capsule formation by several layers of hemocytes �H� in the head-foot region near the tentacle; germinal cell (GC); tegument (T) (h & e) (x 400).