550 
Journal of Agricultural Research 
Vol. XI, No. ii 
With the idea that southern field varieties owe their relative immu¬ 
nity to the thick covering of long husks which protect their ears, it 
seemed worth while to endeavor to breed varieties of sweet corn pos¬ 
sessing numerous long husks. Since the distinctive character of the 
seeds of sweet varieties behaves in hybrids as a Mendelian unit, strains 
that would breed true to the sweet character might be expected in the 
second generation of a cross between field and sweet varieties. It was 
hoped that from the plants producing sweet seeds, strains possessing the 
desired husk characters could be isolated. 
The present paper is an account of an attempt to secure this result, 
with a discussion of some of the factors of worm resistance on which light 
has been thrown in the course of the experiment. 
Even in the worst worm-infested regions it is largely a matter of chance 
whether any particular ear is injured or escapes. To select intelligently, 
it is therefore highly important to know something of the plant characters 
that minimize injury and to use these characters as a basis for selection. 
The study of the characters associated with worm resistance was carried 
on simultaneously with the breeding work, and the value of the results 
is believed to lie in the analysis of the characters and the method of 
breeding quite as much as in the material results. These material results 
comprise two strains of sweet corn possessing marked resistance to the 
corn ear worm. 
PROTECTIVE CHARACTERS 
Four protective characters were in mind at the beginning of the experi¬ 
ment: (i) The distance which the husks extend beyond the tip of the 
ear, with the idea that larvae frequently gain access to the ear by entering 
at the tip of the shoot and eating their way down the silks. It would 
obviously be advantageous to increase the distance they must travel. 
(2) The thickness of the husks' covering. Many ears are found with 
perforations through the husks, and a thicker covering might be ex¬ 
pected to hinder the invasion of the larvae from this direction. (3) The 
texture of the husks. In most sweet varieties the husks are relatively soft 
and smooth, while in field varieties, especially those from the Tropics, 
the husks are firm and harsh. The outer husks of some varieties are 
covered with firm spicules, providing a surface almost as silicious as 
sandpaper. This character might be expected to deter the insects from 
eating their way to the ear through the husks. (4) Husk leaves. It 
was thought that ears without husk leaves might be less attractive to 
moths. 
PLAN OF EXPERIMENTS 
The experiments were begun in 1912. Mr. John H. Kinsler, at Vic¬ 
toria, Tex., made various crosses between three commercial varieties of 
sweet corn, Stowell’s Evergreen, Early Evergreen, and Early Cory, and 
two varieties of field corn, Brownsville and Marrainto. Brownsville is 
