Dec. 1,1925 Size of Sweet-Corn Kernels and Evenness of Maturity 1045 
at the beginning of the season to remain, on an average, relatively 
small throughout most of the season; extreme types at the beginning 
of the season tend strongly to remain extreme types during the whole 
season. This behavior is thought to be the result of internal rather 
than external causes. Reed {12) shows that the seedlings of Helianthus 
follow the same tendency as that described by Pearl and Surface for 
corn. Plants which were small at the beginning were generally small 
at maturity; those which were large at the beginning usually remained 
so throughout the season. He also concluded that this behavior is 
the result of inherent tendencies rather than of external causes. In 
studying garden beans Renich {13) found that large, heavy seeds 
give the best growth and the largest plants. The range of variation 
in size and weight of seedlings is wider between those from small and 
medium-sized seeds than between the medium-sized and large seeds # 
MATERIALS AND METHODS 
Since Country Gentleman is one of the varieties of sweet corn 
that varies most widely in the size of its kernels, it was chosen for 
most of the experiments, although other varieties were used. An 
examination of the kernels showed that on the same ear they varied 
in size from the very slender “shoe-peg” type to the larger and 
broader crowned types (pi. 1, A). These large and small types of 
kernels gave, respectively, large and small seedlings in the germi- 
nator with correspondingly large and small root systems. Disease- 
free seed was used, and it was certain that these differences were the 
result of natural causes and in no way attributable to disease. 
GREENHOUSE TESTS 
In order that their behavior in the soil might be observed, the kernels 
of each type were planted in the greenhouse early in the spring of 1921 
before the weather was warm enough for field planting (pi. 1, B). 
No difference was noted in the time required for the two types to ger¬ 
minate and the seedlings to appear. During the first few days the 
seedlings grew rapidly, but even at this time marked differences were 
evident between the two sets of progeny; those from the small kernels 
were slender with narrow leaves, while those from the large kernels 
were stocky and vigorous and their leaves were wide. 
The greenhouse tests were repeated in the spring of 1922, a larger 
number of kernels of each grade being used than had previously 
been employed. These experiments were made with the double 
purpose of determining the rate of germination of the two grades 
and the relative size of the progeny. The kernels of both types ger¬ 
minated at about the same time, and both varied somewhat, but 
neither had a distinct advantage over the other. Representative 
stalks of both types were transplanted to the field as soon as weather 
conditions would permit the making of careful growth studies. 
The data for these stalks are presented later in the paper. 
FIELD TESTS 
In 1921 a large number of kernels of both types were picked out 
by hand and kept separate for use in field tests. A part of the samples 
Were taken from individual ears and the rest from a shelled bulk 
