1 8 Ph ysiologi(Ml Pre - deter m ination 



thorefore adopted a Copper-Starch soaking treatment followed by liming 

 and re-drying, and record results from which it appears that this treat- 

 ment of the seeds renders them more resistant to fungal attack without 

 affecting their germinating capacity. Moreover, seeds thus treated give 

 rise to plants which are better developed and produce a larger yield 

 than plants from untreated seeds. Breal and Giustiniani drew attention 

 to the fact that from the very beginning of their development the plants 

 from the treated seeds gained on the contrftls, and that the superiority 

 of the yield from the experimental plants over that from the controls 

 was most marked in the case of the " heads." In the two following tables 

 (Tables XII and XIII) the results of the authors' experiments are sum- 

 marised, but these results, although of general economic interest, are 

 unsatisfactory from our point of view because they do not show con- 

 clusively that the copper sulphate has any specific action on the seeds. 

 Taken in conjunction with the beneficial results obtained by simply 

 soaking cereal seeds in water, and in conjunction with the harmful effects 

 of copper-treatments upon seeds recorded by other authors, it seems 

 probable that the improvement of the plants following the copper-starch 

 treatment of the seeds is to be attributed to the soaking alone. 



Table XII. 

 Pot-culture experiment with equal weights of treated and untreated seed. 



For details of the seed-treatments the original paper should be consulted. 



Duration of Weight of the aerial i)arts of plants from treated 

 culture seed, that of the control plants being 



taken as 100 



160 

 122 

 120 

 110 

 119 

 116 



In a later investigation Breal (5) confirmed his previous results 

 and also conducted a number of water-culture experiments with 

 treated and untreated seeds respectively of wheat, oats, barley and 

 maize. These seeds were sown in vessels containing pure water, and the 

 dry weight of the seedlings was taken after various short periods {i.e. 

 25-52 days). It was found (Table XTV) that in each case the total dry 

 weight of the seedlings at the end of the experiment was less than that 

 of the seeds originally sown, but that the plants from the treated seeds 

 weighed considerably more than those from the untreated, this result 



