Abstract
1. The cytological effects of the anti-f ungal antibiotic, Acti-dione, are presented and discussed.
2. Comparative studies of fifteen minute exposures and continuous exposure to concentrations ranging from 1 to 80ppm have been made.
3. An attempt has been made to assay quantitatively the effects of Acti-dione on frequency of mitosis, relative frequencies of different stages of mitosis and rate of increase of aberrations.
4. In general the effects of Acti-dione are similar to those of salts of nucleic acid and superficially similar to those of colchicine.
5. Some treatments show a significant increase in the frequency of various types of “reductional” and “segregational” figures.
