There is no lack of literature showing that this is the 

 explanation favored by many tut it has not been the good 

 fortune of the writer to find any experiments in support 

 of the theory, logical as it certainly seems. 



The subject has been taken up from the standpoint of 

 the influence of large seed upon the yield, of large seed 

 upon germination, of the specific gravity or weight upon 

 the yield, and the relation of the size and weight of the 

 kernel to composition. There has been included also a 

 short discussion of some of the available mechanical aids 

 to the selection of large, heavy seed. 



The Influence of Large Seed upon the Yield. 



Sanborn(2), at the Utah Experiment Station, reports ex- 

 periments to ascertain the effect of using seed separated 

 for size. He used five grades: large, medium, small, or- 

 dinary, and shrivelled. His results are given as follows :- 



: pounds per acre yields: Average 

 Kind of seed. : : 4 years 



:1890 : 1891 : 1892 : 1893 : bu.per A. 



Large 88.5 72.5 111.0 >63.0 18.72 



Mediua 70.0 87.0 67.0 16.60 



Small 94.0 105.0 64.0 74.0 18.72 



Ordinary 84.0 95.0 87.0 29.5 16.42 



Shrivelled 42.0 78.0 31.0 11.25 



His conclusion that very little if any advantage is to 

 be gained by separating seed wheat and planting the large 

 kernels is of questionable value on account of the irregu- 

 larity of the results. 



Latta, at the Indiana Experiment Station, (3) conducted 

 experiments in which wheat was cleaned of chaffy seed and 

 impurities and separated into light and heavy kernels by 



