When sprouts of rye (variety "vyatka") were 

 irradiated by a dose of 250 r two tetraploid plants 

 turned up. Measurements indicated that the 

 diameters of the rootlets and pollen grains 

 showed a noticeable enlargement in the very 

 first year. However, the general behavior of 

 the plants was not any different from that of the 

 normal controls. However, the following year 

 the descendants of these plants (generation XJ 

 had ear glumes of completely unique shape 

 reminding one of the scales of einkorn wheat. 

 As a result of this the ears also had a different 

 appearance from the ears of diploid plants. 



Like other investigators, we observed among 

 irradiated plants many shoots with variegated 

 leaves and many albinos. The latter increased 

 as the dose was increased. The variegation 

 of leaves was extensive: these were mostly 

 plants with yellow or pale yellow stripes on the 

 leaves, which gradually disappeared with age, 

 and the plant would finish its development with 

 leaves of normal green coloring. In some plants, 

 however, this striped condition was retained 

 until the plants were mature. The more pro- 

 nounced the variegation of the leaves, the poorer 

 the development of the plants and the smaller 

 their ears and grains. 



It was also possible to establish a definite 

 regularity in the action of X rays on the behavior 

 of rye. The higher the dosage, the greater the 

 number of dwarfs and poorly developed plants. 



The changes produced by X rays in hemp are 

 extremely interesting. It was possible to ob- 

 serve in hemp all variations described by other 

 investigators in other plants. Hemp seeds 

 (previously soaked for 24 hours) were subjected 

 to gradually increasing dosages of rays ranging 

 from 1000 to 10, 000 r, inclusive. Very soon 

 after being planted the effect of high doses 

 (beginning with 6000 r) began to tell on the 

 development of young plants. They began to lag 

 in size behind the control plants and those which 

 had received small doses. In addition, these 

 plants revealed various morphological changes. 



We observed most frequently a change in the 

 typical bright green coloring of the hemp leaves. 

 White spots of various sizes appeared on them. 

 Sometimes the whole leaf blade would be cov- 

 ered with fine white dots. These variegated 

 patterns sometimes had a sharp contrast be- 

 tween the white and green textures and some- 

 times were washed out and not obvious. In rare 

 cases half of the leaf would be entirely devoid 

 of color (Fig. 10). If the plant reached full 

 maturity, the number of spots on it could be 

 seen to diminish. In addition, these spots 

 would become more colored with time, taking 

 on a yellow, or pale green tint. Plants which 

 received very high doses of X rays exhibited a 

 very interesting peculiarity in the development 

 of their leaves: if the colorless area covered 

 half of the leaf, or slightly less, then that part 



of the leaf would die off with age, but the green 

 part of the leaves would remain viable as long 

 as the plant remained alive. In rare instances 

 genuine variegation of leaves was retained 

 during the whole course of development. These 

 plants had a very handsome appearance. The 

 securing of such variegated forms for decora- 

 tive purposes is worth consideration. The leaf 

 variegation that we observed apparently was 

 caused by irradiation since we did not find a 

 single variegated plant among our controls. It 

 is very interesting to note that as the X ray dose 

 is increased, the number of plants with varie- 

 gated leaves increases, as can be seen from 

 the table below (Table 22). 



Beginning with the 1000 r dose the percentage 

 of plants with variegated leaves invariably in- 

 creases and only with 7000 r does the number of 

 variegated plants fall somewhat in comparison 

 with the action of the 6000 r dose, thus giving 

 the double -humped curve that is typical for the 

 action of X rays. When the doses are raised to 

 9000 and 10, 000 r all the plants at the beginning 

 of their development have variegated leaves; 

 the greater part of these plants, however, dies 

 before reaching the blooming stage. On many 

 plants, particularly on those which had received 

 especially high radiation doses, it is possible to 

 observe deformed leaves. The deformation 

 usually consists of the compound hemp leaf's 

 becoming simple (Fig. 11) or sometimes com- 

 ing to resemble fern leaves. The deformation 

 of leaves becomes more frequent as the dose 

 increases. With doses of 9000 and 10, 000 r all 

 the plants have leaves that are deformed to a 

 greater or lesser extent (Table 22). This phe- 

 nomenon follows the same pattern as in changes 

 of color. Measurements of two-month-old plants 

 indicate that radiation doses up to 4000 r, in- 

 clusively, stimulate the development of the 

 plants (Table 23). 



Apparently, it is necessary to do some work 

 within these limits on the irradiation of hemp 

 seeds, since this experiment shows statistically 

 significant increases in the length of stems 

 following the action of definite doses of radia- 

 tion. Since these data have economic implica- 

 tions they should be considered with redoubled 

 care. Beginning with 5000 r depression of size 

 sets in and with doses of 9000 and 10, 000 r all 

 plants are dwarfs (Fig. 12). However the num- 

 ber of surviving plants is too small to be com- 

 pared with plants which have developed more or 

 less normally; for that reason the data have 

 been excluded from the table. 



In addition to these qualitative changes of 

 stems, dichotomy was observed at various 

 heights, sometimes near the top (Fig. 13), and 

 sometimes near the base of the plant. Another 

 change in the stem is caused by the cessation of 

 development of the top bud, which gives rise to 

 monstrous forms. In some cases this change 

 is accompanied by extreme deformation in the 



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