Unisexual Maize Plants and Their Relation to Dioecism in Other Organisms.

new findings of non-disjunction in autosomes of triploid females and of males carrying inversions in their autosomes seem to be desirable. It should be noted that cases of autosomal non-disjunction in males which carry inversions have already been found by Dobzhansky2 (1933) and by J. Schultz (unpublished). Dobzhansky and Darlington have observed cases of non-disjunction of autosomes cytologically in Drosophila pseudoobscura (unpublished). Summary.-1. No translocations between chromosomes I, II and III of Drosophila melanogaster were found in more than 900 eggs from triploid females and the equal number of spermatozoa from diploid males. 2. Non-disjunction of the autosomes in males, resulting in spermatozoa with two or none of a special pair of autosomes was frequent. 3. Triploid females frequently produced eggs which did not receive any of the chromosomes II or III. For laboratory facilities and for help and advice I am thankful to Drs. T. H. Morgan, C. W. Beadle, Th. Dobzhansky, Barbara McClintock and J. Schultz. 1 Work done-as Fellow of the Rockefeller Foundation-at the Biological Laboratories of the California Institute of Technology, Pasadena, Cal. 2 Dobzhansky, Th., Zeitschr. ind. Abstgsl., 64, 269-309 (1933).