PROCEEDINGS OF SECTION D. 325 



13.— ON THE XEKOPLYTIC CHARACTERS OF HAKEA 

 DACTYLOIDES. 



By A. G. Hamilton. 



14.— THE INFLUENCE OF THE RADIATIONS OF RADIUM 

 UPON THE GERMINATION OF SEEDS (OATS). 



By Dr. Herman Lawrence. 



(Abstract.) 



During the past six montlis the author had carried out' a number 

 of experiments upon this matter, and, although the results agreed in 

 most respects with those obtained in similar experiments carried out 

 by Dr. Abbe, of New York, yet there was one important result obtained 

 by Dr. Abbe which was not supported by the author's experiments. 



Dr. Abbe's results briefly stated were : — 1st. The influence of all 

 the rays from radium upon seeds exposed to them for six days, at a 

 distance of half an inch or less, was that the seeds either failed to 

 germinate, or, on germinating, died within a day or two. 2nd. When 

 the radium rays (the Alpha and soft Beta rays being excluded, leaving 

 chiefly the medium Beta rays, hard Beta and Gamma rays) affected the 

 seeds situated at a distance of | to 1| inches from the radium specimen, 

 these seeds were stimulated as regards their growth when compared 

 with seeds grown under exactly the same conditions, except that they 

 had not been exposed to the radium. This result he believed to be 

 due to a preponderance of medium hard Beta rays, in the radiations 

 obtaining under the conditions of the experiment, at the distances 

 mentioned, Aaz., | to 1| inches from the radium specimen. 3rd. The 

 influence of the rays from the radium, at the distance of 1^ to 4 inches 

 from the specimen, was one of progressive retardation of the growth 

 of the seeds, the plants at 4 inches showing the most marked 

 condition of retardation. The retardation of these growths being 

 compared with seeds similarly grown, but not radiumized. This result 

 he believed to be due to the influence of the hard Beta and Gamma 

 rays, the medium hard Beta rays, with their stimulating effect having 

 been gradually cut out of the potent radiations from the radium 

 specimen. 



The author's experiments, on the other hand, had given total 

 destruction to the seeds exposed within -| of an inch from the radium 

 specimens, and after that distance there was a gradual lessening of the 

 retarding effect of the radiations upon the growth of the seeds, with 

 a stimulating effect upon the seeds at the further distances, up to 

 5 inches and more. The author, however, agreed with Dr. Abbe's 



