Action of Radiations on Viruses 161 



a small fraction of the total bulk of the bacterium, and which is, 

 on our interpretation, to be identified with the genes. 



Inhibition of Division of Bacteria 



Ionization produced in a bacterium but not in the genetical 

 material is not without effect. The most striking effect is a 

 temporary inhibition of division. Bacteria grown in a nutrient 

 medium in the presence of a suitable intensity of radiation con- 

 tinue to grow, in the sense of increasing in volume, but fail to 

 divide. In consequence, rod-shaped bacteria grow into long 

 filaments.^ 



References 



1 Allsopp, C. B. (1944) Trans. Faraday Soc. 40, 79. 



2 Bonet-Maury, P., R. Perault and M. L. Erichsen (1944) Ann. inst. 



Pasteur, 70, 250. 



3 Briiynoghe, R. and W. Mund (1935) Conipt. rend. soc. biol., Paris, 



92, 211. 

 4Friedewald, W. F. and R. S. Anderson (1941) /. Exp. Med. 74, 463. 



5 Green, R. H., T. F. Anderson and J. E. Smadel (1942) /. Exp. Med. 



75, 651. 



6 Lea, D. E. (1940) Nature, Lond. 146, 137. 



''Lea, D. E. (1946) Actions of Radiations on Living Cells, Cambridge 

 [in press]. 



8 Lea, D. E., R. B. Haines and E. Bretscher (1941) /. Hyg. Camb. 



41,1. 



9 Lea, D. E., R. B. Haines and C. A. Coulson (1937) Proc. Roy. Soc. 



B, 123, 1. 



10 Lea, D. E. and M. H. Salaman (1942) Brit. J. Exp. Path. 23, 27. 



11 Lea, D. E. and M. H. Salaman (1946) Proc. Roy. Soc. B, [in press]. 



12 Lea, D. E. and K. M. Smith (1942)-^Parasitology, 34, 227. 



13 Lea, D. E., K. M. Smith, B. Holmes and R. Markham (1944) Para- 



sitology, 36, 110. 

 1-^ Luria, S. (1939) Compf. rend. acad. sci.. Paris, 209, 604. 

 i^'^Muller, H. J. (1922) Amer. Nat. 56, 32. 

 16 Weiss, J. (1944) Nature, Lond. 153, 748. 



