vi FOREWORD 



changes arising from the transfer of this physical energy. Third, 

 an examination of the biochemical effects; and, finally, a discus- 

 sion of the changes occurring in living tissue. Much attention 

 was centered upon the manner in which radiation effects in living 

 tissue should be surveyed. It appeared desirable to avoid numer- 

 ous subdivisions in order to facilitate the handhng of this problem. 

 The committee concluded, therefore, that it should first center on 

 the simplest living unit — the cell — and then transfer directly to 

 the complex living system. The mammalian organism, which 

 would in almost all circumstances be our eventual target, was 

 therefore chosen. The agenda followed closely upon these 

 deliberations. 



It was proposed that the essayists would present the informa- 

 tion available on each of these subjects in its proper background 

 and perspective, giving full development to the subject from its 

 basic aspects through to the most complex. The presentation of 

 original data was to be minimized, such data being utilized only to 

 develop and expound the main thesis. With the material pre- 

 sented in this fashion it was felt that avenues to the solution of 

 existing problems might be pointed up and hiatuses in our present 

 knowledge would be more certainly delineated. Our objectives 

 were fundamental concepts and ideas rather than isolated informa- 

 tion which had not yet found its proper position in radiobiology. 



Although the symposium may not have achieved this ambitious 

 goal, the participants established a very sound basis for further 

 developments and, in a large measure, aided in defining the field of 

 radiobiology. 



Whatever success the symposium may have achieved is due to 

 the essayists, but special mention of their efforts is hardly neces- 

 sary since their approbation will come from the readers who will 

 have an opportunity to examine their collective work. It appears 

 appropriate, however, again to extend our thanks to the foreign 

 scientists. Dr. Walter M. Dale, Dr. George Hevesy, and Dr. Ray- 

 mond Latarjet, who came long distances at the expenditure of 

 considerable time and effort. The labors and unflagging zeal of 

 the members of the special symposium committee, Drs. R. E. 

 Zirkle, A. K. Solomon, J. J. Nickson, M. D. Kamen, H. J. Curtis, 

 and A. M. Brues, were particularly important and contributed 

 greatly to the organization of the symposium. The symposium 

 program was arranged under the five subdivisions already men- 



