44 THE BOTANICAL MAGAZINE. LVoi. xxxvi. m. 424. 



It may be added that in our material all the radicles ceased to 

 grow at about same length irrespective of the intensity of irradiation. 

 This is also borne out in the study of sections ; mitoses are very 

 seldom met with and mechanical tissues has developed, while in the 

 control preparations I can find numerous mitotic figures, no dif- 

 ferentiation of mechanical tissues having taken place. 



It seems to me that the effect of Rontgen rays upon the seeds 

 is slowly progressive and manifests itself as injurious to cell elements 

 at a certain stage of the seedlings after normal cell division continued 

 up to that stage, as is attested by our findings from the study of 

 radicles of irradiated seeds. 



I happened to learn through verbal communication with Prof. 

 Kimura. that he saw in the tumor cells of the horse testis following 

 types of nuclei : 



1) young tumor nuclei are small and filled with uniformly 

 distributed chromatin network and generally have no nucleolus. 



2) medium sized nuclei provided with a less quantity of 

 chromatin nets and with nucleoli. 



3) abnormally enlarged nuclei which have a little chromatin 

 and many nucleoli, sometimes vacuolated. As this type of nuclei 

 has been observed among old cells of tumor, it may indicate 

 senescence. 



I have had the opportunity of looking over his preparations of 

 tumor (carcinom of the horse testis and polymorphic sarcom of 

 man) and found the above types of nuclei, irregularity in the state 

 of nuclei, but rarely came across abnormal mitotic figures such as 

 asymmetrical and multipolar mitoses. I have seen the finely 

 vacuolated nucleolus in a medium sized nucleus in the horse case, 

 and multinucleated cells in both cases. 



Comments. 



It will be too bold to compare the changes of cell elements of 

 my case directly with those of carcinom, yet, degenerative changes 

 of tumor cells as I saw in the case of testis-carcinom of the horse, 

 have interesting resemblance to those of mine so much so that it 

 simply means a coincidence. It may safely be said that irradiation 

 of X-rays (large dose) upon the seed of Vicia faba leads the cells of 

 radicles to a diseased or senescent condition resembling that of 

 tumor cells. 



