ABSTRACT
Manifestation of mitotic activity of colchicin in 4- and 5-day-old chick embryos was studied under different modes of colchicin injection into the eggs. Three methods were tested: colchicin solution was injected into the serous-amniotic cavity (1) and into the yolk sac (2) and also by dripping on the serous membrane over the enbryo (3). Perfect metastatic effect was observed only when colchicin was used in concentration of 1 X 10(-4) g/ml and injected by the third mehtod. Increase in the solution volume over 0.1 ml resulted in a greater percentage of embryo death. Lack of a definite inhibitory action after colchicin injection into the serous-amniotic cavity might be explained by decrease of the substance concentration as a result of its dilution by the cavity fluid. A complete lack of blocked mitoses in the embryo tissues after colchicin injection into the yolk sac can be explained, according to the authors, by the presence, in the yolk, of a great number of ovoflavins capable to inhibit mitotic activity of colchicin.