FIGURE 2. Differences in development of rye depending on the dosage of X rays they had received, 



number of stems per plant increases with favor- 

 able dosages as development proceeds. With a 

 dose of 250 r the number of stems per plant is not 

 much greater than that of the controls, but the 

 number of ears at harvest time is almost triple 

 that of the controls, and this does not include 

 the number of underdeveloped (those which had 

 failed to catch up) ears of the same stems. 



If we had not carried our experiments through 

 harvest time, we would have had to agree with 

 those authors who point to the small stimulating 

 effect of X rays or to the total absence of this 

 effect. 



The seeds (investigations of Breslavets and 

 Afanas'eva)* received the same X-ray dosages 

 as the sprouts, but these dosages produced a 

 different effect on the development of the plants. 

 Just as had been done with the irradiated sprouts, 

 the soaked irradiated seeds were planted in 

 flower pots and on the twenty -seventh day trans- 

 ferred to field plots. When we set out the flower 

 pots according to dosages, we saw a very vivid 



example of the curve of the Arndt-Schultze Law. 

 (Fig. 2). 



In order to check our direct observations by 

 means of figures, we measured all the plants on 

 the twenty -seventh day after planting. As may 

 be seen in Table 4, the numerical data coincide 

 with the visual evaluation. 



If we carefully examine our irradiated plants 

 and compare them with the controls when both 

 are in the process of growing additional stems, 

 some interesting details can be brought to light. 

 The first thing that attracts attention is the 

 increased size of the leaves; their breadth and 

 coloring are directly related to the dosages. 

 With doses of 250 r it was not possible to find 

 any obvious differences from the controls, but 

 with doses of 500 r the greater width and darker 

 green coloring of the leaves were immediately 

 apparent. Doses of 750 r intensify these charac- 

 teristics still more. The climax is reached with 

 doses of 1000 r when the width of the leaves is 

 nearly double that of the controls. Beginning 

 with 2000 r the size of the leaves first approaches 



Dose, (r) 



Control 

 250 

 500 

 750 



Table 4 

 (based on the data of Breslavets and Afanas'eva, 1932) 



Average 

 Length, cm 



12.5 

 20.0 

 23.9 

 22.8 



Average 



Bushiness 



(Number of 



Stems/Plant) 



2.0 

 2.6 

 3.1 

 3.1 



Dose, (r) 



1000 

 2000 

 4000 

 8000 



Average 



Bushiness 



(Number of 



Stems/Plant) 



3.2 

 2.0 

 2.6 

 1.6 



17 



