Jan. io, 1914 
Environmental Influences on Wheat 
283 
PHYSICAL CHARACTERISTICS 
WEIGHT OF 1,000 GRAINS OF WHEAT 
In California the grains were almost uniformly plump and heavy, not 
varying far from 30 grams for each thousand, except in the case of the 
samples grown on the soil obtained from Maryland. In Kansas they 
were less plump, 1,000 grains weighing about 23 grams in 1910, 13 grams 
in 1911, and 20 grams in 1912. In Maryland the weight of 1,000 grains 
was quite uniform throughout the series of four years. As a rule, the size 
of the grains in each locality for each year was uniform, irrespective of 
the type of soil in which they grew. There were, however, a few notable 
exceptions to this rule: The grain grown on Maryland soil in each year 
from 1909 to 1912 in California, as well as that grown on the Maryland 
soil in 1912 in Kansas, was decidedly lighter in weight than that grown 
in the same locality on the other soils. This would seem to indicate that 
some soils play an important part in influencing the size of the grain. 
Between the localities there was usually a much greater difference in 
the weight of 1,000 grains than was noted between the soils. (See Table II.) 
The weight of 1,000 grains, then, is distinctly dependent, as a rule, on 
climatic or seasonal conditions rather than on soil characteristics. The 
fact that environment plays the chief r61e in influencing the weight is 
again brought out in the tables of averages, which show a great difference, 
for example, 30.2, 19.1, and 25.6 grams for California, Kansas, and 
Maryland, respectively, when averaged by localities (see Table III), and 
a relative uniformity of 26.5, 27.9, and 22.1 grams, respectively, when 
averaged by source of soil (see Table IV). 
Table I shows that in about 80 per cent of the samples investigated 
the weight of 1,000 grains of seed grown on different soils in any one 
locality was sufficiently uniform to permit the conclusion that climate 
and not soil is the chief factor affecting the size of the grain. From 
Table III it is seen that the California-grown samples averaged the 
heaviest and the Kansas-grown samples the lightest. 
WEIGHT OF ONE BUSHEL OF WHEAT 
The weight of a bushel of wheat runs more or less parallel with the 
weight of 1,000 grains. If the samples weighing over 61 pounds to the 
bushel are compared with those weighing less than 60 pounds, it will be 
found that the weight of 1,000 grains of the former was, on an average, 
33.4 grams, and that of the latter, 25 grams. In many cases, owing to 
the small amount of material, it was impossible to make a weight-by¬ 
bushel determination. 
FLINTY GRAINS 
Classifying the grains of each sample into those which were wholly 
dark or flinty and those which appeared to be light brown or mealy, a 
remarkable uniformity is found in the groups arranged by locality in 
