EDITOR'S COMMENTS 



This book by Breslavets was published in Moscow in 1946. It is an interesting and 

 useful summary of the older literature in plant radiobiology and covers much Russian work 

 that has not been reviewed previously in the English language and includes some otherwise 

 unpublished data. 



The book will no doubt be a controversial one because some of the conclusions reached 

 by the author are not generally accepted outside the USSR. One such view is that X rays 

 stimulate (increase) plant growth or yield to a degree that could be economically useful. This 

 conclusion receives little or no support from recent work outside of the USSR and is even 

 questioned in some recent Russian publications. 



A number of corrections have been made in the English version and other possible 

 errors have been commented on in footnotes. Many references mentioned in the text were 

 omitted from the bibliography in the original Russian version; these are marked with one 

 asterisk (*). The original bibliography has been checked carefully and many errors corrected. 

 However, a number of references in the bibliographies could not be confirmed; these are 

 marked with two asterisks (**). The present version has combined both Russian and non- 

 Russian references, which formerly were listed separately, into a single list for each chapter. 

 The following abbreviations have been used which the author did not use: roentgen unit (r); 

 skin erythema dose (HED); and Holtzknect unit (H). Skin erythema dose is that dose which 

 will produce a standard amount of erythema or reddening of the skin in a standard patient in 

 about three weeks. It is equivalent to about 800 roentgens. The Holtzknect unit (H) is approx- 

 imately one -fifth of a skin erythema dose. These two radiation units are no longer in current 

 usage and have been superseded almost completely by the more recently introduced units, 

 roentgen and rad. 



It is hoped that in spite of the time lapse since the publication of the Russian edition, 

 the English version of the book will be sufficiently useful to botanists and radiobiologists to 

 justify the cost and effort of translating and producing it. 



Acknowledgment is hereby made for the assistance of the U.S. Atomic Energy Commis- 

 sion in the publication of this translation. 



Arnold H. Sparrow 



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