THE EFFECTS OF RADIUM RAYS ON METABOLISM AND 

 GROWTH IN SEEDS. 



By ALFRED C. REDFIELD and ELIZABETH M. BRIGHT. 

 {From the Laboratory of Physiology, Harvard Medical School, Boston?) 



(Received for publication, October 18, 192L) 



The view is current in the literature on the physiological action of 

 radium radiations that these rays produce their effects by altering the 

 metabolism of the tissues exposed to them. The basis for this view 

 appears to be the observation that exposure to radium changes the 

 rate of cell division and growth. If the term metabolism is to be used 

 in describing the reaction of organized matter to any reagent, in order 

 to attain analytical significance it must be defined in terms of some 

 definite set of chemical transformations. We have consequently 

 carried out a series of experiments designed to test the effect of the 

 /3-rays of radium on those metabolic processes which result in the 

 production of CO2 and to demonstrate whether any correlation exists 

 between alterations produced in these activities and the ability of the 

 protoplasm to take part in cell division and growth. 



It is essential for such an experiment to select material which will 

 enter into some well defined growth process, and of which the CO2 

 production can be examined before any change in the bulk of proto- 

 plasm has brought about a significant alteration in the quantity of 

 CO2 produced. For this purpose we have made use of radish seeds, 

 and have measured the CO2 given off, before germination has had time 

 to take place. Doubtless, cell division and growth were beginning 

 to take place while the measurements were being made, but any 

 changes in CO2 production which occurred as a result were not suffici- 

 ent to mask the effects produced by the radiations. 



The output of CO2 was measured in the apparatus described by 

 Osterhout.^ Fifty or seventy seeds were moistened and spread over 

 the surface of a test-tube. Air was circulated between this test-tube 



1 Osterhout, W. J. V., /. Gen. Physiol, 1918-19, i, 17. 



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