74 Richard H. Boerker 
conclusive. Only in the case of the corn was there a sufficient 
difference to warrant a conclusion in favor of the heavy seed. 
From the results of these experiments it seems logical to conclude 
that in general more vigorous growth and consequently a better 
stand in the field is secured by employing only the heavier seed. 
The effect of the size and weight of seed on production has been 
with no other plant so extensively studied as in the case of the 
wheat. The majority of results seem to favor the view that large 
and heavy seed are preferable. Zavitz (28) showed that the 
yield in bushels per acre was in favor of the large plump seed. 
Trabut (32) found in the case of tobacco seeds that it was 
possible to affect a separation into heavy and light sorts through 
the capacity of these two kinds respectively to sink and float in 
water. It was found that the heavy seed produced plants which 
were greener, more vigorous, and of larger size. The yield from 
plants from the heavy seed was almost double that of the yield 
from the light seed. Shamel (31) secured results similar to 
these. Careful comparative tests of the light and heavy seeds of 
tobacco have proved that the best developed and most vigorous 
plants are always produced from the large, heavy seed while the 
light seed produce small, irregular and undesirable plants. In 
an experiment with Cuban tobacco seed Shamel found the 
germination of heavy seeds almost perfect while less than five 
per cent. of the light seeds sprouted. The plants from the heavy 
seed grew more rapidly than those from the light seed and 
reached the proper size for transplanting seven to nine days 
earlier than the plants from the light seed. 
In the case of cotton seed, comparative production tests of the 
value of the heavy seed over the usual farm product have been 
made by the U. S. Department of Agriculture (30). The yields 
in pounds on equal areas in South Carolina show the gain from 
the use of heavy seed in two different cases to be 10.9 per cent. 
and 8.25 per cent. respectively. 
Bolley (29) selected large and small grains from the same 
heads of wheat and found that the large grains generally pro- 
duced the largest yields. Waldron (29) found that short wheat 
culms, shortheads, and those with a smaller number of grains 
