Evaluation of the effect of some chemicals on the larval stages of Schistosoma mansoni (in and coming out of the snail intermediate host )

First of all thanks to Allah.I’m very gratefull to Prof. Dr.Samia El-Sayed Etewa.Professor of Parasitology,Faculty of Medicine,Zagazig University,Prof. Dr. Mohammed Hegab ,Professor of Parasitology,Faculty of Medecine ,Zagazig University and Dr. Mona Abd El-Hakim Matter,lecturer of Parasitology ,Faculty of Medicine,Zagazig University for their limitless help and kind advise throughout this work.I would like to express my deep respect to Prof. Dr. Laila Ali Abo El Magd,Professor and Head of Parasitology Department,Faculty of Medecine,Zagazig University.I can’t express my great thanks to Pr. Dr.Nashat Abd El-Monem Nasif,Professor and head of Parasitology Department,Faculty of Medecine,Monofia University and Pr.Dr.Soad Mahmoud Yossif,Professor of Parasitology,Faculty of Medecine ,Zagazig University for their presence and participating the discussion of this thesis which titled…………..