20 Physiolofiical Pre-deterinmation 



seedling, it is impossible on the, basis of the data given to determine the 

 factors responsible for the results obtained. Breal, however, is satisfied 

 to conclude that the treatment ensures a better utilisation of the seed- 

 reserves. 



In view of the results obtained by Breal and Giustiniani, which, as 

 we have pointed out, cannot be attributed in the absence of further 

 evidence to the specific action of the copper, the recent critical work of 

 Jungelson(i7), who worked with maize, is of interest. Jungelson used 

 simple solutions of various copper salts and obtained similar results 

 whatever the nature of the anion, thus definitely indicating that copper 

 is the main factor in producing the results. He also showed that the 

 results varied with the concentration of the salt. 



The effects of the copper treatment on the seeds showed themselves 

 throughout the whole course of development and were even carried over 

 into succeeding generations. These effects, however, although very dis- 

 tinct and characteristic, were altogether harmful from the point of view 

 of vigour and yield. Firstly, the copper treatment of the seeds decreases 

 their power of germination, and secondly, there is both a retardation of 

 the vegetative development and a delay in the flowering of the plants 

 produced. Thirdly, a tendency towards variation, which manifests itself 

 in the appearance of abnormal "heads" and seeds, is shown by the plants 

 from the treated seeds ; but these new characters do not appear to be 

 handed on to the next generation. Lastly, plants from seeds treated in 

 identically the same way exhibit totally different abnormaUties. 



Jungelson's results are especially important from two points of view ; 

 firstly, they demonstrate the persistence of the effect of the copper 

 treatment of the seeds, and secondly they prove that the results of 

 treating seeds with copper are distinctly unsatisfactory. Jungelson 

 himself suggests that the degeneration of local races of cereals, which has 

 become so marked of late years, may in a certain measure be due to the 

 general use of seed-treatments in which copper is employed for the 

 purpose of preventing the development of smut. 



(II) Other salts. 



We have already indicated the possibility that such results as those 

 obtained by Breal and Giustiniani (fi) may be due to the soaking in- 

 volved in their treatment of the seed rather than to the action of the 

 copper. This possibility must be borne in mind when the question of 

 other seed-treatments which involve soaking for certain periods in 

 solutions of various salts is under consideration. 



