Jan. 1022,] KOMURO : -EFFECT OF RONTGEN RAYS 17 



Comments. 



From what has been written it will be seen that the amount of 

 crop in Oryza sativa is not at all increased by the irradiation of X- 

 rays. The writer is rather inclined to believe the increase of the 

 amount of crop due to irradiation as described in the paper by 

 Yamada and Nakamura may not be a real one. (Should they take 

 more care in cultivating the plants, their results might agree with 

 mine.) Culture experiment were given up, because of the difficulty 

 of avoiding the external effects and of the increased expenses to carry 

 out the experiments. 



The writer takes great pleasure in acknowledging here his in- 

 debtedness to Prof. Kiiti Miyake who has kindly allowed him to 

 use Wagner's pots and other equipments required for the experi- 

 ments. Through the generosity of Mr. Kazutita Okura the writer 

 was able to use rice-fields. He is also obliged to Baron Kaisaku 

 Morimura and Dr. Mataro Nagayo for the trouble they have taken 

 for the writer. Thanks are also due to the Homei Kwai for the 

 expenses for the present research. Last, but not least, the author 

 ought to express his hearty thanks to Messrs Kqji Kato and Kiyoo 

 Tabuti for their kindly help rendered during both field and laboratoy 

 works of this research. 



Botanical Institute, College of Agriculture, 



Imperial University, Tokyo. August, 1921. 



