Homozygous males produce 43-49% gametes exceptional for sex chromosomes and 39-44% exceptional for chromosome 4. Sex and fourth chromosomes misassort independently. Consistently produce an excess of nullo-X-nullo-Y over XY-bearing gametes, but nullo-4 and diplo-4 gametes equally frequent. Nondisjunction confined to first meiotic division. Chromosomes 2 and 3 also give high frequencies of nondisjunction; appear to disjoin randomly based on chromosome analysis of secondary spermatocytes. Primary spermatocytes show mostly univalents; MII appears normal except for the non-haploid complements resulting from MI chromosome misbehavior. Spermatids often contain micronuclei and nullo exceptions are more frequent than diplo exceptions, both indicative of chromosome loss.