58 Nebraska Agricultural Exp. Station, Research Bui. 11 
of 12 years of continuous use of the fanning mill in securing the 
heaviest one-fourth of the seed each year for planting, no definite 
appreciable improvement has been effected. 
HISTORICAL SUMMARY OF INVESTIGATIONS WITH GRADES 
OF SMALL GRAIN SEEDS 
Numerous tests have been made comparing the yielding 
qualities of large and small or light and heavy seeds. Various 
methods of testing have been employed by the various in- 
vestigators and the results are not all directly comparable with 
one another. 
The separations have been made in part by the use of hand 
screens. In other experiments, some form of fanning mill has 
been employed. Again, part of the grades have been separated 
by hand selection of large and small seeds. The outcome of all 
methods was to secure distinct grades of seed, altho the most 
clearly defined and uniform grades were doubtless secured by 
the hand selection. 
Some of the experiments have been made in large field plats, 
while others have been made in small nursery plats. The small 
nursery plats are regarded as quite reliable if sufficiently rephcated. 
Some investigations have extended over a period of years, while 
others are of only a single year duration. In some, replication of 
plats has been practiced and in others not. In a number of 
cases, the tests have been made in pots under laboratory condi- 
tions. Several experiments also report the relative yields of large 
and small seed when grown alone and when grown in competition 
with each other. 
The various grades under comparison have also been planted 
in equal numbers, equal weights, and equal volumes, at the 
normal rates for the large seed. In several tests they have been 
space-planted to permit maximum development of the individual 
plant. 
In some investigations, continuous selection has been practiced 
by taking seed of a given grade each year from the crop grown 
from that same grade the previous year. This would permit an 
accumulative effect. 
Some experiments have compared only large and small seed, 
while others have also included the original unselected seed in 
the test. 
All of these conditions, as far as they are reported in bulletins, 
together with the yields obtained, have been summarized briefly 
in tables 37 and 38. Tables 39 to 45 are general compilations 
from tables 37 and 38, secured in some instances by averaging 
data given by the investigator to fit the particular requirements 
of the table. 
