[Thermal-temporal patterns and temporal program of development of poikilothermic animals in the light of the data obtained using dimensionless criteria of duration of development (tau(n)/tau(0))].

An attempt was undertaken to generalize and interpret the data on thermal-temporal patterns of development of the poikilothermic animals obtained using relative criteria of development duration.

Evolution of the histological and functional structure of ectoderm, chordamesoderm and their derivatives in Anamnia.

The paper considers the appearance of differences in the structure of "primary ectoderm", i.e. of the presumptive ectoderm and chordamesoderm material in different chordates, and offers evidence that these differences foreshadow the structural peculiarities of early embryogenesis in different groups of Anamnia.

Maturation of Rana temporaria and Acipenser stellatus oocytes induced by the cytoplasm of embryos at different cell cycle phases and at different stages of cleavage and blastulation.

Experiments involving injections of cytoplasm from the cleaving embryos of Rana temporaria and Acipenser stellatus into fully grown oocytes of the same species and of Xenopus laevis, show that at all mitotic phases, and throughout the period of synchronous cleavage divisions, the cytoplasm is characterized by high activity of the germinal vesicle breakdown factor. This activity decreases during nuclear division desynchronization and drops sharply after the mitotic index fall upon blastulation. Aside from germinal vesicle breakdown in the oocytes, the A.