288 HIDEO KOMUBO. 



to develop at almost tlie same stage of growth imder the groimd. There 

 is no difference in gi'owth proportional to the doses given (when the steepsd 

 seeds contain same amount of water by steeping). 



(3) When the dose of Röntgen rays exceeds a certain limit, it does not 

 iudnce a visible difference in the state of impediment proportional to the doae. 

 The effect of Königen rays iu these eases is no more than an injurious 

 stimulation for the seeds — of coui-sa, this hmit varies with the water contents 

 of the seeds at the time of irradiation. 



From these facts, the writer thinks it may Ije presumed that strongly 

 irradiated seeds are particularly affected at the plumule and radicle, and 

 metabohc change of these pai'ts may take pkce, and when this change reaches 

 a certain stage, the seedhngs cease to develop. 



Neuberg's statement in his paper entitled " Beziehungen des Lebens zum 

 Licht " may be of interest in this connectioii : " Das sind Eeaktionen, die den 

 Ablauf des Stoffsvechsels iu einer belichtetsu Zelle völhg ändern können. Da 

 ■die Photokatalysen den Abbau hochmoleknlai'er Substanzen, ähnlich wie 

 Enzyme, besorgen, kann man sich vorstehen, daß tei damiederhegendem Stoff- 

 wechsel das Licht eine anregende Wirkung dadurch entfaltet, daß es in 

 gewissen Sinne die RoUe von Fermenten iitemimmt oder dm'ch Bildung von 

 anomalen und besonders i-eaktionsFähigen Spaltiuigsprodukten (Aldehyden, Keto- 

 säm-en u. dgl.) ungewöhnliche Beize ausübt " (p. 54). 



A simimary of the results of our experiments, in adchtion tj the specially 

 stated three facts, is as follows: — 



(1) Though air-diied seeds with a water content of 10.5^ were exposed 

 to rays of 7H-15H, there occun-cd no acceleration of germination. 



(2) Though ak-dried seeds having ca. 14o% water are exposed to rays of 

 40 H and \vp and steeped seeds of 57% up to 10 H, the day of sprouting and 

 bloom is not accelerated, they are rather delayed accordmg to the increase of 

 the dose. 



(3) Tlie effect of X-rays varies with the water contents of the seeds at 

 the moment of m-adiation. Even in the air-dried seeds an impediment occurred 

 according to the water content and the doses given. 



(4) Seeds having a water content of 57°^ and up seem to luvve been 

 severely affected by 20 H up. 



