462 RADIATION INJURY AND LETHALITY 



ferences between species have shown up; (6) the relation between the 

 early and late slopes; and (c) the possibility of later recovery functions 

 than those described here. 



2. It is important to correlate measurable physiological and pathologi- 

 cal states with vital statistics data. 



3. Using life-table characteristics of large populations, we should re- 

 evaluate the chronic lethal pattern in relation to the widely differing 

 life spans of different species. 



4. Studies similar to those described here, relating to a variety of other 

 insults (for example, chemical carcinogenic agents and industrial poi- 

 sons), have been seriously neglected. 



5. The relation of dosage rate or duration of administration to effect, 

 where the dosage is delivered within a few hours, demands further in- 

 quiry. 



6. The carcinogenic pattern needs further investigation, especially as 

 to whether there is a time limitation on the development of tumors after 

 the primary insult. 



7. By the analysis of mammalian radiation injury and lethality it 

 should be possible to gain much further information as to the under- 

 lying mechanisms by the proper use of various qualities of radiation (as 

 neutrons and gamma rays) . We are now in a position to begin to apply 

 the elegant methods currently employed in cytological and other basic 

 work to the analysis of the mammalian mechanisms. 



REFERENCES 



1. Jacobson, L. O., E. K. Marks, M. J. Robson, E. 0. Gaston, and R. E. Zirkle, 

 The effect of spleen protection on mortality following X-irradiation, /. Lab. 

 Clin. Med., 34: 1538-1543, 1949. 



2. Van Dyke, D. C, and R. L. HufT, Epilation of the non-irradiated member of 

 parabiotically united rats, Proc. Soc. Exptl. Biol. Med., 72: 266-269, 1949. 



3. Kaplan, H. S., Local irradiation and the induction of lymphoid tumors in mice, 

 Cancer Research, 9: 621, 1949. 



4. Hagen, C. W., and G. A. Sacher, Effects of X rays on rabbits. I. Mortality after 

 single and paired doses, CH-3754 (MDDC-1252), 1946. 



5. Murray, R., M. Pierce, and L. O. Jacobson, The histological effects of X rays on 

 chickens with special reference to the peripheral blood and hematopoietic organs, 

 CH-3873, 1948. 



6. Karnofsky, D. A., personal communication, 1949. 



7. Steamer, S. P., E. J. B. Christian, and A. M. Brues, Progress Report: Effect 

 of X irradiation on blood uric acid in the chick. Biological and Medical Divisions, 

 Argonne National Laboratorj^, February, March, April, 1950, A. M. Brues (ed.), 

 Quart. Rept. ANL-4451 (unclassified), pp. 77-78. 



8. Painter, E. E., C. L. Prosser, and M. Moore, Physiological observations on 

 rabbits exposed to single doses of X raj's, CH-3227, 1945. 



