down; however, irradiation of aqueous solutions 

 of the juice of red beets does not confirm this 

 assumption. The discoloration is apparently 

 due to acids, which are liberated as a result of 

 the change in permeability. An additional factor 

 is the passage of solutions from the cell, thus 

 diminishing the pressure of the cell sap. When 

 the time of irradiation was extended, the speed 

 of protoplasmic streaming was reduced, as has 

 been pointed out earlier. The surface of the 

 protoplasm became more and more irregular and 

 some cells became strongly vacuolized. In 

 order to determine whether this process is 

 reversible, Williams transferred the cells into 

 distilled water. However, the process of 

 shrinkage of the protoplasm continued in the 

 water; consequently, this process was not 

 reversible. 



The experiments of Lopriore, Seckt, and 

 Williams establish in essence the change of 

 viscosity due to the effect of X rays on various 

 plant objects. Weber (1923) set up special ex- 

 periments for the measurement of viscosity in 

 protoplasm of cells after X irradiation. The 

 first experiments were set up with Spirogyra . 

 The dosage used was 170 H. After an hour the 

 ability of the chlorophyll band to settle out under 

 centrifugation was tested. After a five-minute 

 period of centrifugation, the displacement was 

 identical with that of the controls. Consequently, 

 Weber did not succeed in detecting a change in 

 the cytoplasm as a result of the primary effect 

 of X rays. However, when the five -minute 

 centrifugation was performed 20 hours after 

 irradiation, a remarkable difference in the dis- 

 placement of the chromatophores was observed. 

 In the non- irradiated controls of Spirogyra the 

 displacement of chromatophores took place in 

 88% of the cells, while the X-rayed chromato- 

 phores were not displaced at all. Another ex- 

 periment with identical irradiation of filaments 

 of Spirogyra was performed 24 hours after irra- 

 diation. Only 15% of the cells showed displace- 

 ment of the chromatophores, while in the con- 

 trols 84% of the cells exhibited displacement. 

 Forty-eight hours after irradiation, the irradi- 

 ated and unirradiated cells remained the same. 

 From these experiments it follows that one hour 

 after irradiation there is no change in the vis- 

 cosity of the plasma, after 24 to 48 hours the 

 viscosity of the irradiated cells increases. 

 Consequently, the secondary effect of X rays is 

 observed. With the given dose of X rays, no 

 morphological changes in Spirogyra were re- 

 vealed and further experiments were not suc- 

 cessful. 



Weber selected for his second experiment 

 shoots of Phaseolus multiflorus. When he irra- 

 diated them with a dose of 24 H they did not 

 manifest any changes in viscosity. Nor did he 

 find any changes in the viscosity of protoplasm 

 in the rootlets of this plant, despite the fact that 

 they are extremely sensitive to all kinds of 

 [ionizing] radiation. From this Weber concludes 



that changes in viscosity do not take place in 

 living plant protoplasm as a result of primary 

 action. Weber considers this quite understand- 

 able since the primary action affects not the 

 cytoplasm but the karyoplasm, which carries a 

 different electrical charge. He concludes that 

 the viscosity of the nucleus changes from the 

 fact that the nucleolus slips out of it under 

 centrifugation. 



The Japanese scientist Komuro published 

 several works devoted to investigations of 

 cellular changes induced by X rays. These 

 were actually the first detailed cytological 

 studies. In his investigations (1922) of the 

 effects of this type of radiant energy on the root 

 tips of Vicia faba, he showed the changes that 

 took place in them. Subsequent authors merely 

 carried these studies further and investigated 

 in more detail. Root cells raised from seeds 

 which received 50 H manifested a multiplicity 

 of nuclei, increase in size of cells and nuclei, 

 vacuolization of nucleolus and cytoplasm, 

 increase in the number of nucleoli, and diminu- 

 tion of chromatin material. In the periblem 

 some cells were found to be in a condition of 

 karyolysis and others in the state of pycnosis. 

 In his next work Komuro (1924a) investigated 

 changes at various intervals after irradiation of 

 the same object. These observations showed 

 him the sequence of the phenomena that he 

 described in his earlier work. One and a half 

 hours after irradiation, vacuolization of the 

 cytoplasm, chromatolysis, and irregularity of 

 mitoses were observed. After 6 hours, degen- 

 eration of the nuclear membrane, pycnosis, 

 karyolysis, and appearance of abnormal binucle- 

 ate cells were observed in addition to previous 

 changes. After 9 hours, giant nuclei and nuclei 

 with numerous nucleoli were observed in addi- 

 tion to the other changes. In his paper, Komuro 

 stresses the similarity of these changes to those 

 in malignant tumors. 



This similarity is brought out still more 

 strongly in his following work (1924[b]) where 

 he investigated the effects of X rays of various 

 strengths. Seeds of Vicia faba of the same 

 variety, "Hyogo, " were soaked in water for 72 

 hours and, after irradiation with doses of 20 to 

 40, and 50 H, were planted in sand. Their roots 

 were fixed after 8 days. He did not observe 

 any significant differences in the action of these 

 three doses, but he described in greater detail 

 those changes which arise in cells as a result 

 of irradiation. Among general changes, the 

 extreme rarity of mitoses and their multipolar- 

 ity or dispersion of chromosomes through the 

 cytoplasm, are characteristic. In addition, 

 withdrawal of the protoplasts from the cell wall 

 (in which case the cytoplasm becomes condensed 

 or very vacuolated) was also observed. 



The author used these objects to study the 

 formation of binucleate cells and showed that 

 they can arise by various means: 1) by 



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