STODIDS IN THE EFFFCT OF RÖKTGEN RAYS, ETC. 289 



(5) From tho fact tluit soedliuga from irnvdiiitcd seeds, whether peeled or 

 not, pyovr alike, it is presumed that the presenoo of the seed coat does uot 

 affftct the p;crmiiiatioii. That is, a dose above 20H became au injurious 

 stimnLition for tlio pUimulo and radicle in steeped irradiated secdg with ca. ^S% 

 water. 



(G) The sprouting of aii'-dried irnuliated seeds is delayed more than that 

 of steeped invitliated ones. Tlio retardation of sprouting may Ixs due to the 

 fjict, that the latter, whoso watsr content i3 large, are more stimulated tluui 

 the former having less water. If the sprouting is delayed, the growth will d) 

 S3, and a retardation of the time of bloom will natiurally take phice. 



At the cud of this pajier, it is the wxitcr's pleasant duty to ackjiowletlge 

 his indebtedness to Dr. KOiti Fpjinami, Mho has made irradiations for him, 

 and helped him in every way throughout the progress of the work, and to 

 Professors KiiCHi Miyake and Keita Shibata who have given kind advice 

 and criticism. Tlie vniter is also indebted ^to Dr. Mataro Nagato, who 

 kindly miido arrangements with the Mürdiura Homei Kwai to defray the 

 expenses of this study. Thanks are also due to Prof. Naohide Yatsü for his 

 kindness in making valuable suggestions as tj the form ajid other partlcnL^r.^ 

 of this paper. 



Botanical Institute, Colled of Agricultiu-e, 

 Imperial University, Tokyo. 

 Juno, 1922. 



