[An analytical study of the patterns of the survival curves of experimental objects in model experiments on Daphnia magna.]

The phenomenon of multiphase survival curves found in drosophila is confirmed in experiments on daphnia. Mathematical modeling showed that the multiphase nature of the daphnia survival curves reflects abrupt changes in the intensity of death of crustaceans during the transition from phase to phase. In intact daphnia there is no phase of a sharp increase in mortality observed at an early age in drosophila. It arises as a reaction to weak negative influences, which leads to a sharp decrease in the survival of young individuals. A logical conclusion was made about the readiness for reaction of each experimental individual. The effect was observed in a series of experiments posed in different years. It is proved that in daphnia, the predisposition to reaction persists for an indefinitely large number of generations. It is postulated that this reaction has an epigenetic nature. Previous experimental materials suggest that a reaction of this type is widespread in natural surroundings.

[On the discontinuity of the annuity curves in Drosophila melanogaster Canton-S strain. IV. Effect of low temperature on the early imaginal stage].

We tested the effect of low temperature (18-20 °C) applied at the 13-22 days of imago life. We detected prolongation of individual life span. The effect is due to prolongation of the first phase of the annuity curve and thus to further delay of the next ones. This may lead to delay of mature pathology and prolongation of maximal life span. The effect is not dependent on sample size.