This report describes a genetic study of salivary map region 39DE of the Drosophila genome, which is known to include the histone gene sequences (Pardue 1975; Liftonet al. 1977). Small deficiences extending proximally into 39DE were constructed by the segmental aneuploid method of Lindsleyet al. (1972). The translocational deficiencies obtained in this manner were gamma-irradiated to remove the Y translocational arms. One of these newly reconstituted deficiencies was then used to screen 10,000 gamma-irradiated second chromosomes for lethal mutations. The 32 lethals recovered from the screen were tested against several deficiencies and markers, crossed inter se and categorized according to their genetic properties. From these data, a preliminary complementation map was constructed of salivary region 39A-39F. The salivary map positions of certain of the complementation groups suggest that the mutants in these groups may affect histone gene functions.