vered exposures; continuous life-time irradiation; the effect of dose-rate, the effect of fractionation; chronic terminated exposures; and the effects of radiation of different quality. The various contributions will be examined under the section thought to be more relevant to the subject matter under discussion. However, a certain amount of overlapping and repetition is unavoid- able in order to compare the various conditions of irradiation. A. 60. THE EFFECTS OF ACUTE SINGLE DOSES In the following paragraphs the effect on long-term survival of acutely- delivered single doses of radiation will be examined. The data will be re- viewed with the criterion of considering together all information pertaining to a given species, roughly arranged according to the time of publication in order to give some historical perspective and a feeling of the state of the field at any given time. Since it was often found that data on low- or high- LET radiation were included in the paper, the review will consider together the information pertaining to different types of radiation. A summary of the numerical values to be derived from the documents reviewed is given in Tables 1 and 2, where low- and high-LET data are tabulated separately. 1. 61. The earliest data of Gowen and Stadler 'G2/, Grahn and Sacher [G3], Furth et al. et al. [F2], Kallman and Kohn |K7], Storer and Sanders [517], Storer [S18], Boone [B8, B9] and Nowell and Cole |N4#] will only be mentioned in this context. from Tables 62. Mouse 1 The essential information in these reports may be derived and 2. In 1960 Upton et al. [U5] reported on a very extensive series of data (the Greenhouse experiment) on late effects including life-shortening in LAF1 mice (6 to 12 weeks old) exposed at a nuclear test site. Nineteen groups of 220 mice each were exposed to gamma rays from 179 to 782 rad. doses in 8 groups ranged from 28 to 250 rad. Neutron Mean survival times were ob- tained for each exposure group and tested for linearity versus dose. In both sexes, for the gamma as well as for the neutron data, significant departures from linearity were observed and the best interpolation to these data was a curvilinear quadratic relationship fitted empirically. The authors felt that