42 L. H. GRAY 



Dewey, D. L., and Boag, Z. W. (1960). Z. NaturJ. 6, 372. 



Ehrenberg, L., (195.5). Bot. Notiser 108, 184. 



Gillies, N. E., and Alper, T. (1959). Nature, Lond. 183, 237. 



Gray, L. H.. Green, F. O., and Hawes, C. A. (1958). Nature, Lond. 182, 952. 



Hewitt, H. B. and Wilson, C. W. (1959). Brit. J. Cancer 13, 675. 



Hollaender, a., Stapleton, G. E., and Martin F. L. (1951) Nature, Lond. 167, 103. 



Howard -Flanders, P. (1957). Nature, Land. 180, 1191. 



Howard -Flanders, P. (1958). Advanc. biol. med. Phys. 6, 553. 



Howard -Flanders, P., and Alper, T. (1957). Radn Res. 7, 518. 



Howard -Flanders, P., and Jockey. P. (1960). Radn Res. 13, 466. 



Howard-Flanders, P. and Moore, D. (1958). Radn Res. 9, 442. 



Keilin, J. (1955). Biochem. J. 59, 571. 



KiHLMAN, B. A. (1958). Expl. Cell. Res. 14, 639. 



KiHLMAN, B. A. (1959). Nature, Lond. 183, 976. 



KoNZAK, C. F., XiLAN, R. A., Legault. R. R., and Heiner, R. E. (1960). Proc. Sijnip. 

 "Effects of Ionizing Radiation on Seeds and their Significance for Crop Improvement." 

 In press. 



Laser, H. (1960). Brit. J. Radiol. 33, 341 (Abstr.). 



Lea, D. E., and Salaman, M. H. (1942). Proc. ray. Soc. B123, 1. 



LiPETZ, L. E. (1960). In "Immediate and Low Level Effects of Ionising Radiations," 

 p. 227. Taylor and Francis, London. 



Marcovich, H. (1958). In "Organic Peroxides in Radiobiology", p. 117. (M. HaissinskIy, 

 ed.) Pergamon Press, London. 



MousTACCHi, E. (1958). Ann. Inst. Pasteur, 94, 89. 



NiLAN, R. A.. KoNZAK, C. F., Legault. R. R.. and Harle, J. R. (1960). Proc. Symp. 

 "Effects of Ionizing Radiations on Seeds and their Significance for Crop Improve- 

 ment." IAEA. In press. 



Platzman, R., and Franck:, J. (1958). In "Information Theory in Biology" p. 262. 

 Pergamon Press. London. 



Porter, G., and Windsor, M. W. (1958). Proc. roy. Soc. A 245, 238. 



Powers, E. L., and Kaleta, B. F. (1961). In press. 



Powers, E. L., Ehret, C. F., and Bannon, A. (1957). Appd. Microbiol. 5, 61. 



Preer, J. R. (1948). Amer. Nat. 82, 35. 



Sparrman, B., Ehrenberg, L.. and Ehrenberg, A. (1959). Acta chem. scand. 13, 199. 



Stapleton, G. E., Billen, D., and Hollaender, A. (1953). J. cell, conip. Physiol. 41, 

 345. 



WiTKix, E. M. (1956). Cold Spring Harbour Sipnp. quant. Biol. 21, 123. 



Wolff, S. (1959). Radn Res. Suppl. 1, 453. 



Wolff, S. (1960). Proc. Synip. "Effects of Ionizing Radiation on Seeds and their Signifi- 

 cance for Crop Improvement." IAEA. In press. 



ZiMMER, K. G. (1960). "Studien zur ciuantitativen Strahlenbiologie." Akademie der 

 Wissenschaften und der Literatur. 



DISCUSSION 



EiDus : At what doses was there a bend in the dose curves in the experiments under 

 anaerobic conditions ? 



GRAY: The Hnes were straight throughout. 



EIDUS : I would like to point out that in well-known experiments by Dr. Hollaen- 

 der on E. colt the dose curve under anaerobiosis after the initial bend runs, over 

 several orders of magnitude, parallel to the first curve characteristic for the aero- 

 bic conditions, whereas in your exiaeriments there is always a divergence of the 

 curves. What is the explanation for this difference in the results? 



GRAY : For the cell suspensions we have used, the form of the curves may differ 

 slightly, but in general they are very similar. 



