242 Journal of Agricultural Research voi. xii, no. s 



been eliminated from recent experiments, but the effects of selection 

 are so pronounced and speedy that in experiments hitherto reported 

 any direct effect of the environment on the characters of the plants 

 would be completely masked. The characteristics of a maize variety 

 are altered readily by selection. When grown in a new locality for a 

 few years, even without conscious selection, the type may change rapidly; 

 and when brought back to the original locality, it is in reality a differ- 

 ent variety. The characters brought into prominence in the new locality 

 may render the stock less suited to the old conditions, though better 

 adapted to the new. 



It would be very difficult, if not impossible, to eliminate completely 

 all selective action. Even when all seed is saved, those individuals or 

 types of plants which are best adapted to the conditions under which 

 they are grown will produce a greater proportion of the seed than will 

 the types which are less well adapted, and those least adapted may 

 produce no seed at all. In two localities where different conditions 

 prevail, the highest yielding plants — hence those contributing the largest 

 proportion of the seed — would presumably be of different types; and 

 when brought together and compared, we shou^ld expect to find a slight 

 advantage for the locally grown seed. Yet the results of the present 

 experiments indicate that the effect of selection during a single season 

 may be so slight as not to mask completely the opposing new-place effect. 



Since new-place effect in maize seems to operate as a stimulus, it would 

 tend to obscure any lack of adaptation in newly introduced varieties. 

 The recognition of new-place effect may be said, therefore, to increase 

 rather than diminish the importance that must be assigned to adaptation. 



As a result of the stimulation due to new-place effect, the cultivation 

 of an inferior strain might be extended as a result of its satisfactory per- 

 formance the first year following its introduction. 



The stimulus that followed the transfer of seed in these experiments is 

 doubtless similar to the increased vigor imparted to many vegetables 

 by growing the crop in localities remote from the place where the seed 

 was produced. The economic utilization of increased vigor secured in 

 this way is usually confined to crops which are grown for the sake of some 

 part other than the seed. In cotton, for example, the increase of vigor 

 in the plants following a transfer of seed is often very pronounced, 

 although the crop of seed and fiber may be reduced. In maize, as a 

 result of the determinate habit of the plant, vegetative vigor and seed 

 production are more closely associated, so that the possibility of prac- 

 tical utilization seems greater. 



CONCLUSIONS 



Hybrids between the same pairs of varieties made at different local- 

 ities showed no decrease in yield as a result of transferring the first- 

 generation seed to a new locality. On the contrary, the change of 



