STUDIES IX THE EFFECT OF KÜKTGEX RAYS, ETC. 2C3 



Viciu /aba, " Hyogo ", gi-owii from iiTjiilifited seeds. The cells of tlio r.nliclc 

 of tlie 5011 iiTadiiited ssecls showed obiiuges, snch ns foniuitiou of multiuncleated 

 cells, eiiLirgemeut of Iwth tlie cell aaid the uiideus, vdcuolizatiou of both the 

 nucleolus luid the cytjplasui, mciaise of tha uumher of uucleoh and decre.ose of 

 chromatic sulstauca. Mitises are veiy seldom met with and almost »11 cases 

 were anomalous, the chromosjmes liaviug bscome fragmentary and scattered in 

 tlie cytoplasm, and mechanical tissues develojied, while in tlie couti'ols ho 

 could find numerous mitotic figiu-es, no differentiation of n:echanical tissues 

 having taken pLice. In the iieriUem tissue many ceUs are foimd m karyoljüc 

 condition and others in jiyknosis. Even in the tissue adjacaut to the growing 

 point pykuotic cells are foimd. It is interesting to find, that these changes 

 resemble those of tumor cells (especially in the tjstis-carciuora of the horse). It 

 may safely Ije said tliat irradiation of X-rays (lai'ge dose) upon the seeds of 

 Ficia /aba leads the ceUs of raclickfi to a diseased or senescent condition 

 i-csembhng that of tumor ceEs. 



Tlie results of the alx)ve mentioned authors can be summed up as 

 follows : — 



1. Röntgen rays have a harmful effect on the seeds proportional to the 

 water contents of seeds. 



2. The seeds, which are late in genninating, as Vicia /aba, were stimu- 

 lated by Köntgen rays. Tlie germination of Cahjstegia hederacea, Oenanfhe 

 stolom/cra and Oryza saliva was accelarated. 



3. To iiTadiate the seeds with a moderate dose before sowing gp.vo good 

 results for the gi-owth of the plants ('. e., it became a positive stimulus. 



4. The inmliatiou of younger pkuts does not produce any acceleration of 

 growth and affects them rather harmfulh- proportional to the degi'eo of dose. 



5. The plants have different sensibihty to Röntgen rays, /. c, they show 

 " selective alsoi-ption ". 



G. In weak irradiation, the hanufulness of the rays is projpoi-tional to 

 theii' intensity-. 



7. Even if wc ex^wse seeds containing much water to a high dose of 

 Röntgen rays, we cannot make the seeds stop theii' development immediately. 

 They genninate and develop for a ceiiain time. 



8. According to the cytological obseixation of the tip of radicles &-om 



