studies in the Effect of Röntgen Kays upon the 

 Development of Vicia faba'. 



By 



Hideo Komuro. 



With Plates XI-XII and oue Text-figme. 



co^TE^■TS. 



1. Introduction. 



2. Uistorical survey of the effect of Königen rays ripon the higher plants. 



3. Culture experiments. 



4. Germination experiments. 



5. Discussion. 



I. Introduction. 



From the experiments caiTied out dining a, j^^eriod extending from MiU'ch 

 1917 to April 1922 with intemiption of some months the -ni-iter obtained the 

 following new facts besides several other results. Sti'onglr iiTadiated seeds in 

 air-dried and steeped condition do not stop their development immediately, 

 they germinate and develop for a, cert;^in period. Spronts from iiradiated 

 steeped seeds containing much water do not appear above the soil and 

 their development ceases at almost the same stage of growth under the ground 

 irresiDcctive of doses given. AVhen the dose of Röntgen rays exceeds a certttiu 

 limit, no diCorence is seen in the state of impediment proportional to the dose 

 and their effect is no more than an iujmious stimulation to the seeds. 



From the alx)ve result? tl«; ^^Titer pi-esumes that sti'ongly in'adiated seeds 



1. The present work \rns carried out by a grant from the Moktmuk.! Homei Kwai. The 

 main part of this paper was read before two meetings of the " TOkyS Igakkwai " (Tokyo Medi- 

 cal Society) on Xov. 5, 1917, and on Oct. G, 1919, incorporating the results of germination- 

 experiments which were made during Juu ', 1919, and published in .Japane&c in the " Irigakii 

 EyohO Zasshi" (1918), the Tokyo Botanical Magazine (1919 and 192D) and in the " Keio Igaku" 

 (1921). 



