“…The data from these experiments have indicated that the cysts of E. histolytica were much more sensitive to gamma rays than the trophozoites. However, the work with trophozoites (Schneider and Porter, 1960) was performed with a different strain and at a different time. Thus, it seemed advisable to compare the reactions of cysts and trophozoites of t,he same strain by irradiating them together.…”