The purpose of the study was to determine the influence of various types of water environment and hydrostatic pressure in various temperatures and with or without participation of daylight on embryogenesis and hatching of miracidiums of liver fluke. The study materials were the eggs of Fasciola hepatica. The influence of temperature (21±1 ^oC, 24±1 ^oC, 30±1 ^oC), daylight and darkness on embryogenesis in eggs situated in physiological liquid, tap water, puddle water, in 1% water solution of ammonium phosphate and potassium oxide mixture, which is use for fertilization of meadows, was observed. For determination of developmental stages was used the Kowalska’s embryogenesis key [1990]. The principial influence of temperature on development of eggs of Fasciola hepatica was observed. With the temperature growth, decrease the time differences, which results from influence of another factors on embryogenesis. The results of trial obtained in vitro suggest, that agrotechnical operations (fertilization of meadows and pastures) probably have an effect on embryogenesis and population of miracidiums of Fasciola hepatica. It needs a verification in further field trials.

45-51