Selection of Elementary Species 117 



one must undertake under his own conditions. 

 Some varieties will prove, after isolation, to 

 be profitable for large districts and perhaps 

 for whole states. Others will be found to be 

 of more local value, but in such localities to excel 

 all others. 



As an example we may take one of the varie- 

 ties of wheat originated by the Minnesota Ex- 

 periment Station. Hays described it as fol- 

 lows. It was originated from a single plant. 

 From among 400 plants of " Blue stem " sev- 

 eral of the best were chosen, each growing sep- 

 arately, a foot apart in every direction. Each of 

 the selected plants yielded 500 or more grains of 

 wheat, weighing 10 or more grams. The seeds 

 from these selected plants were raised for a few 

 years until sufficient was obtained to sow a 

 plot. Then for several years the new strains 

 were grown in a field beside the parent-variety. 

 One of them was so much superior that all 

 others were discarded. It was the one named 

 " Minnesota No. 169." For a large area of 

 Minnesota this wheat seems capable of yielding 

 at least 1 or 2 bushels more grain per acre than 

 its parent variety, which is the best kind com- 

 monly and almost universally found on the 

 farms in southern and central Minnesota. 



It would be quite superfluous for our present 

 purpose to give more instances. The fact of 



