Abstract
Chromosome ends involved in non-homologous terminal adhesions were studied. The physical nature of the phenomenon was investigated with the aid of a micromanipulator. The chromosomes involved in the end-to-end sticking were stretched until the ends broke apart. No case was found in which the ends had gained or lost a band. The genetical nature of adhesions was investigated by determining which chromosomes were involved most frequently and it was concluded that the frequency with which any 2 chromosome ends adhere together is non-random, differs in different strains, is subject to change over a period of time, is not affected by the genotype of the cytoplasm nor temp. However, the total incidence of adhesion is affected by temp. A foreign chromosome end introduced into a strain demonstrated that the specificities shown in terminal adhesions are char- acteristics of the end itself, and revealed potential abilities of ends which are not realized under normal conditions.