The Bulletin. 11 



cumuiative effect of seed selection and adaptation. 



It is generally true that any variety of plant will sport or change, 

 even though it be kept on the soil to which it is specially adapted, but 

 the variations in this case are generally in the desired direction. 



The Minnesota Experiment Station, after many careful experiments 

 to determine the effect ol growing the same kind of plant in the same 

 kind of soil (not in the same field, however), for a number of years in 

 succession, concludes : "The old idea that seed tended to run out when 

 grown too long on the same soil is false," At the Nebraska Experiment 

 Station a new variety of wheat was introduced some years ago and 

 grown for several generations on the same type of soil (the Marshall silt 

 loam). As the variety adapted itself to the new soil environment the 

 yields increased. The seed was carefully graded each year and the 

 variety showed a tendency toward continual improvement. Mr. W. W. 

 Toole, the originator of the Toole variety of cotton, has for years been 

 improving his cotton along the lines of early maturity and increased 

 proportion of lint to seed. He now has not only one of the earliest ma- 

 turing varieties, but one in which he has increased the per cent of lint 

 from 38 to 44. He tells me, moreover, that within a short time he 

 expects to put on the market an extra early variety, yielding 46 per cent 

 lint, and that within ten years he will produce a cotton yielding as high 

 as 50 per cent lint. 



We thus see that when careful seed selection is combined with uniform 

 soil conditions, the variations of the plant are cumulative in the desired 

 direction. 



