Abstract
SUMMARY: The behaviour of the chromosomes of diploid strains of Saccharomyces cerevisiae was studied in organisms which had been treated with snail digestive juice after fixation, and then stained with the HCl—Giemsa stain. Coagulation of chromatin was observed after late prophase-I in some strains and for this reason the chromosome number of these strains could not be determined. One diploid strain (H 102 x H 9) showed no chromatin coagulation, and was shown to have eighteen bivalents at metaphase-I.