[Hereditary melanotic tumors of Drosophila. Determination of the tumorous transformation of larva hemocytes].

Two different phenomena contribute to the histogenesis of melanotic formations in tumoral strains of drosophila : an abnormal multiplication of certain blood cells and their encapsulation by normal hemocytes. The statistical distribution of melanotic tumors in populations of individuals submitted during precise periods of their life to the action of agents such as supraoptimal temperature or ionizing radiations, permits to suggest for the tumoral transformation of larval hemocytes in drosophila, the following mechanism : this transformation is caused by an event occuring in the cytoplasm and determined by the activity of a nuclear gene.