esculenta . In the first experiment (1924), the 

 differences in the germination rate among indi- 

 vidual seeds (both control and irradiated ones) 

 were so great that the author refused to ascribe 

 any effect to the X rays. Ancel repeated the 

 experiments of Maldiney and Thouvenin with the 

 seeds they had used ( Convolvulus and Lepidium) 

 and likewise obtained negative results. In the 

 next experiment (1925a) she demonstrated the 

 importance of the role played by the temperature 

 at which the seeds germinate after being irradi- 

 ated. A lower temperature (10° to 14°C) 

 increases the injuries because of high X-ray 

 doses; a higher temperature (20° to 25°) reduces 

 them. In her third work (1925b) she raised the 

 question of the significance of the time interval 

 from the moment of exposure to the moment of 

 the appearance of injuries resulting from X 

 rays. All of her experiments indicate that the 

 intensity of injuries caused by X rays are a 

 function of the time from the moment of irradia- 

 tion: the longer the time interval, the more 

 pronounced the appearance of injury. In her 

 fourth paper Ancel (1926) examined in detail the 

 effects of irradiation on individual parts of 

 plants (in this case, lentils and beans). In one 

 of the numerous (but identical as far as results 

 were concerned) experiments dry lentil seeds 

 were exposed to doses of 40, 70, 100, and 

 150 H. When individual parts of the plants were 

 measured on the 14th day after irradiation, it 

 was discovered that injuries caused by X rays 

 were not identical for various plant parts. On 

 the basis of these data we have set up the follow- 

 ing table in order to facilitate comparison. 

 (Table 1). 



This table indicates that laterals are most 

 susceptible to injury; secondly, the main root; 

 and, finally, the stem. Similar results were 

 obtained in studying the percentage of injuries 

 in beans. Finally, in experiments devoted to 

 determinating stimulating doses of X rays for 

 dormant buds of lentils, the author (1926) 

 argues against the experiments of Weber, who 

 had established the stimulation [by irradiation] 

 of such buds in lilacs. She subjected 16 sprouts 

 of lentils (whose stems ranged from 8 to 10 mm 

 and whose roots were protected by plates of 

 leaded rubber) to doses of 8 H. On the fifth day 

 after irradiation two dormant buds (located on 



the sides of the stem base) began to develop. 

 On the tenth day after irradiation the stems had 

 reached the length of 46 millimeters, and the 

 buds produced additional shoots with an average 

 length of 16 millimeters; while on the control 

 plants the buds showed no development. This 

 experiment provided the basis for believing that 

 stimulating doses of X rays exist. However, if 

 the stem is cut off after it reaches 100 milli- 

 meters in height, the buds will produce addi- 

 tional shoots. This fact caused Ancel to believe 

 that, in the X-ray experiment, it was the injury 

 of the stem by the radiation, and not the effect 

 of irradiation which caused the buds to grow. 

 In order to determine if injury of the stem by 

 X rays will produce the same effect as cutting, 

 she irradiated the stem with doses of 20 and 

 40 H; the dormant buds began to develop as they 

 had after the main stem was removed. In other 

 experiments, when the whole plant (except for 

 the roots) was subjected to radiation, the stem 

 ceased to develop, and the buds remained 

 dormant: apparently, the dose was so great 

 that it injured the buds as well. From her 

 experiments Ancel concluded that the develop- 

 ment of buds in her experiments with X rays 

 was caused by the phenomenon of compensation 

 resulting from injury to the stem, and not from 

 the stimulating action of X rays on the buds. 



A. V. Kol'tsov and L. I. Kol'tsova (1925) set 

 up experiments with irradiation of pea and wheat 

 seeds. They exposed dry and germinated seeds 

 of Triticum vulgare lutescens to various X ray 

 dosages, but they did not note differences in the 

 onset of various phases. In individual cases 

 an increase of total weight was observed in 

 irradiated plants, but it was not possible to 

 arrive at any kind of definite conclusions. Ex- 

 periments with peas gave more definite results 

 as far as acceleration of development was con- 

 cerned. For example, the plants bloomed 3 to 

 4 days earlier than the controls. However, the 

 total weights varied to such an extent in their 

 experiments that the authors were unable to 

 establish any rule to which irradiated peas 

 conformed. 



Bersa (1926) attempted to approach the work 

 of previous investigators critically. For ex- 

 ample, he considered that the work of Schwarz, 



Table 1 

 (based on Ancel' s data, 1927) 



