constriction of the nucleus, 2) by budding of the 

 nucleus, and 3) by asymmetrical mitosis. As 

 for the formation of polynuclear cells (those with 

 more than 3 nuclei), they arise as a result of 

 inhibition of the development of the cell wall in 

 conjunction with one of the following processes: 

 1) tripolar mitosis, 2) a division of one of the 

 cells in a tri -nuclear cell, 3) the exclusion of 

 some of the chromosomes or parts of the chromo- 

 somes from the division of the nucleus in the 

 telophase, and 4) the irregular distribution of 

 chromosomes in the anaphase. Komuro explains 

 the formation of bi- and polynuclear cells by a 

 lowering of the viability (senility) of part of the 

 protoplasm, i. e. , the inability of the protoplasm 

 to increase sufficiently for normal division. 



In addition to the above phenomena, he ob- 

 served an increase in the size of nuclei and 

 nucleoli, eccentric position of nucleoli in the 

 nuclei with the separation of the chromatin ma- 

 terial from it, vacuolization of nucleoli, and 

 also the slipping out of nucleoli from the nuclei. 

 Occasionally giant nuclei arose which filled the 

 entire cell: they took hematoxylin stain strongly 

 and contained several pale nucleoli. All these 

 phenomena were accompanied by pycnosis and 

 karyolysis. The increase of the size of the cells, 

 nuclei, and nucleoli, the hyper- and hypochro- 

 matic condition of the nuclei, according to 

 Komuro, all indicate a degenerative or senile 

 condition of the tissues. Komuro considers all 

 these phenomena reminiscent of the conditions 

 found in the cells of malignant tumors. This 

 resemblance in changes he confirmed by his 

 experiments both with the action of X rays and 

 with tar on the rootlets of Vicia faba and Pisum . 

 sativum (1927). And, in a fourth article 

 (I928[a]), Komuro mentions the appearance of 

 tumors on the roots of Vicia faba due to irradia- 

 tion. In the cells of the tumor one finds cells 

 showing normal cell division as well as cells 

 which are in a state of disintegration. This 

 observation shows that tumor cells continue to 

 grow until they die. It is remarkable that lateral 

 roots develop completely normally without form- 

 ing any nodules. 



Strangeways and Oakley, [(1924) and Strange- 

 ways and Hopwood (1926)] observed changes in 

 cellular tissues immediately after irradiation 

 or else 80 minutes later. In the initial series 

 of experiments, the first abnormality to be noted 

 was the appearance of a granular condition of 

 the chromosomes in the metaphase and anaphase. 

 As the X-ray exposure time was increased, a 

 greater number of cells showed this abnormality, 

 granular changes in the chromosomes became 

 more distinct, and finally some of the chromo- 

 somes underwent fragmentation. Following a 

 more prolonged period of radiation (60 minutes), 

 the cytoplasm also becomes granular and less 

 dense. At the same time, the outline of the 

 cells changes and becomes abnormal, and the 

 cytoplasm breaks up into separate parts. In 

 other cells, the nucleus and cytoplasm suddenly 



fall apart and a ray-like structure appears. 

 This ray-like structure arises from small areas 

 of the protoplasm, some of which contain large 

 or tiny droplets of nuclear material. Finally, 

 the cells become so disorganized that only 

 shadows of dispersed fragments of the nucleus 

 and cytoplasm remain. Eventually, even they 

 vanish and all traces of the cell and the nucleus 

 disappear. These experiments show with 

 remarkable clarity the growth of changes as 

 doses are increased. However, they fail to 

 show whether the action of the radiation takes 

 effect immediately or whether there is a defi- 

 nite latent period. In order to clarify this 

 question, the authors transferred the irradiated 

 cultures into an incubator for 80 minutes. An 

 examination of these cultures revealed that a 

 period of 15 to 20 minutes is essential for the 

 action of X rays to become manifest. 



KOrnicke [1905] after irradiating roots of 

 Vicia faba observed the appearance of waviness 

 on them which he ascribes to internal differ- 

 ences in tension. KOrnicke traced this to an 

 enlargement of the transverse diameter of the 

 cells in the phloem parenchyma of the root. 

 The folds, which were observed in the external 

 parts of the phloem, changed the direction of 

 growth of the cells. The cells of the epidermis 

 that were caught in the corners of the fold were 

 crushed. The author observed the presence of 

 binuclear and polynuclear cells in the periblem 

 and plerome. But KOrnicke did not find any 

 injury to the cytoplasm. Thus, the earliest 

 radiobiological experiments established that the 

 destructive power of X rays is proportional to 

 the dosage used. 



The majority of workers who investigated 

 the effect of X rays on cells performed their 

 experiments in such a manner that the primary 

 effect of X rays on cells were not distinct from 

 the indirect effects, which depend on the reaction 

 of the organism as a whole. With this consider- 

 ation in mind, Strangeways and Hopwood [1926] 

 used the embryonic tissues of chicks in a drop 

 of nutrient solution for their experiments. 

 These cultures revealed a wide zone of cells 

 with 20 to 100 mitotic figures. Division of the 

 unirradiated cells requires from 40 to 50 min- 

 utes under these conditions. A whole series of 

 experiments performed by these authors indi- 

 cates that the diminution in the number of cells 

 undergoing mitosis, which may be noted 80 

 minutes after irradiation, is not observed 

 immediately after irradiation. When stronger 

 doses of X rays were used, the authors observed 

 fragmentation of the chromosomes, their sepa- 

 ration or delay at anaphase, and sometimes 

 fragmentation of the cells. When the dosages 

 are increased, the number of abnormal cells 

 increases as well as the number of bipolar and 

 multipolar cells, and then the number of frag- 

 mented cells increases. In order to establish 

 the reason for the decrease of mitoses, the 

 entire series of experiments was subjected to 



59 



