variation, Nilsson, after some preliminary experiments, 

 arrived at the conclusion that no new, pure or constant 

 strains of wheat could be obtained unless the fruit of a 

 single ear was bred separately, and thus he established 

 what is known as the principle of breeding from the single 

 ear and not from assorted lots of seed taken from many 

 individuals. This breeding he continued, picking out any 

 chance favorable ear which he could find, until he obtained 

 many thousands of different forms owing to this multi- 

 plicity of strains mixed in the ordinary wheat. Of course 

 some turned out to be mere bastard strains and only the 

 ones which continued to breed true to character were kept. 

 These constituted the new agricultural varieties, in real- 

 ity elementary species and mutants which, after severe 

 tests had proved them suitable, were raised in marketable 

 quantity for seed. The amount of work involved was 

 enormous, the mere bookkeeping of the accurate pedigree 

 record with notes on the life history of each form and its 

 progeny was in itself no small matter. Besides the prin- 

 ciple of single-ear breeding, Nilsson also established the 

 fact that but a single selection alone is necessary to fix 

 a new strain, provided the progeny of the chosen ear are 

 carefully guarded from admixture with other forms. All 

 this seems absurdly simple, and it is simple, so much so 

 that it is quite possible of application by a person of aver- 

 age intelligence who has had the proper instruction, but 

 the important point is that it was discovered by the appli- 

 cation of thoroughly scientific methods. Nilsson's princi- 

 ple is in very general application today and is being used 

 to excellent effect in the improvement of Indian corn in 

 the middle West. 



Contrast with this the methods of Mr. Burbank, whose 

 name is familiar to all. It is not that he should not be 

 given the credit of having established new and useful 

 strains of cultivated plants, or of having done some 



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