The Effect of Chemicals on Mitosis Studied in Tradescantia Cells in vivo. II

Hydrazino-tropone compounds

Abstract

1. By means of the agar plate method, the action of 2-hydrazino-tropone and 7-bromo-2-hydrazino-tropone on mitotic cells was investigated in the Tradescantia test in vivo.
2. In a certain range of concentrations of these tropone compounds, swelling of the nucleus, of the cytoplasm and of the chromosomes occurs. In this state, not only the swollen prophase nuclei can continue the mitotic processes but also mitosis occurs de novo; most of the mitotic cells, however, become binucleate cells by the disorganization of the phragmoplast in the telophase.
3. These tropone compounds scarcely act on the atractoplasm, but due to the stickiness of the swollen chromosomes sometimes introduce bridges merely in appearance in the telophase.
4. From the standpoint of the cell biology, the relationships between the swelling of the prophase nuclei and the disorganization of the phragmoplast and the susceptibility of the prophase nuclei are discussed.