SUMMARYChronic irradiations of mice with 3-cm microwaves, carried out at the University of California during the past several years, have shown no clear effects on longevity at the sublethal doses employed. Some other effects, notably with regard to cancer of the white cells and testicular damage, resulted from this pilot study. A detailed description of the results appears in Trans. IRE BME-9: 104-108, 1962.This report also contains a summary of the results obtained by P. 0. Vogelhut in irradiating enzymes at the same wavelength; these results are described in greater detail in another report (Issue No. 476) in this Series.