Abstract
Twenty-one of the multispored asci which consisted of five, six, seven and eight spores of Saccharomyces were chosen and dissected with the aid of a micromanipulator. The hybrid culture used was a heterozygous for eleven genes, among which, the genes controlling mating types, caffeine sensitivities, choline, isoleucine, phenylalanine, arginine and lysine requirements were tested. Data suggest that asci with more than four spores consist of two (or more) sets of different tetrads, and that some of the tetrads would be expected to arise through the degeneration of half of eight nuclei of the multispored ascus. The intra-cell behaviour can cause irregular segregations on the basis of the mendelian laws.
