Dec. io, 1917 Breeding Sweet Corn Resistant to the Corn Earworm 557 
DISCUSSION OF RESULTS 
The results of the 1916 experiments will first be examined to determine 
whether they corroborate the 1915 data in showing that there are sig¬ 
nificant differences among the progenies in the extent of damage. 
An examination of the average damage of the different progenies 
(Table IV, column 2) shows the results to be in fair accord with those 
of the previous year and shows even more clearly that the differences in 
the extent of damage are not the result of accident. 
Phi24, again the least damaged of all the progenies, is with one excep¬ 
tion separated from all other progenies by significant differences. The 
exception, PI1140, is a descendant of PI1124, produced in 1915, the male 
parent being a plant of PI1123. From the remaining progenies PI1124 is 
separated by differences that range from 2.4 to 16.5 times the probable error. 
It may be seen also that Oregon Evergreen, Pi29, one of the com¬ 
mercial varieties included in the experiment, was damaged more than 
any of the hybrid progenies except PI1127, PI1127C1, and PI1128C2. 
One of these, PI1127C1, is the only progeny in which the difference is sig¬ 
nificant. Oregon Evergreen was chosen for comparison as one of the 
most worm-resistant of the commercial varieties of sweet com. It is 
also the variety most generally grown in the worm-infested regions of 
the Southwest. The relatively high damage in the two Hopi hybrids 
Phi 37 and PI1141 should also be noted. The following notes were taken 
on an Eastern variety of sweet com grown by the side of the worm- 
proof com experiment and maturing at the same time. 
Prolongation. 2. o±o. 2 
Number of larvae. 2, 4± .1 
Damage. 3. 8± .4 
Degree of maturity. 8. g± .4 
Since the days from silking to harvest were not recorded for the 
variety, it is not included in Table IV. The degree of maturity was lower 
than in any of the wormproof progenies, and, since damage is negatively 
correlated with maturity, the comparison is believed to be in no way 
unfair. The damage to this variety was nearly 3 times that of the 
wormproof progeny with the greatest damage, and 29 times that of the 
progeny least damaged. As a further comparison the average damage 
to Golden Bantam sweet com growing in a garden about % mile from the 
experiment was found to be 2.6 ±0.5. 
Considering only the 14 rows planted from the same lots of seed as 
the 1915 experiment (marked with an asterisk in Table IV), it will be 
seen that the row least damaged in 1915 was also the least damaged in 
1916. Beyond this, while it can be seen that there is a general agree¬ 
ment, there are many changes in the standing of the progenies. Most 
of these differences are doubtless to be ascribed to chance variations, 
for the determinations are by their nature subject to wide fluctuations. 
It should be kept in mind, however, that the two experiments were tried 
