(3 Nebraska Agricultural Exy. Station , Research Bui. 20 
Many of the plant characters which are involved in adapta- 
tion are not inherited singly, but commonly go in groups of 
associated characters. As a consequence the selection for some 
single specific character is frequently attended by the indirect 
selection of a group of characters. Some of the adaptive char- 
acters which tend strongly to be associated or transmitted in 
groups are early maturity, small stature, ears low on the stalk, 
small leaf area, slender ears, and smooth, shallow kernels with 
horny endosperm. Selection toward the opposite extreme of any 
of these characters tends to result in a rather corresponding 
transition in all of the other associated characters. Exceptions 
occasionally occur to these groupings of plant characters. 
2. Continuous selection within a commercial variety at this 
Station during four years for opposite extremes in the ratio of 
leaf area to dry plant substance resulted in seven “high leaf 
area” and nine “low leaf area” strains of corn, in which the 
former, in comparison with the latter, averaged 23 per cent more 
leaf area per unit dry matter, 29 per cent greater actual leaf 
area, and five days later maturity. The high leaf area selections 
had ears of larger circumference, and deep, rough, starchy grain, 
whereas the low leaf area strains had more slender ears, with 
smooth, shallow, horny kernels. In a succeeding seven-year 
yield test, the low leaf area yielded 7 per cent more shelled corn 
per acre than the high leaf area type, but produced 4 per cent 
less than the original corn from which it was selected. An F 1 
cross between these two leaf area types yielded 2 per cent more 
than the original corn during the seven years. The data suggest 
superiority of the low leaf over the high leaf area strains but 
also that some reduction in yield has resulted from narrow 
breeding brought about by too restricted type selection. 
3. Annual selections of various ear types of a standard 
local variety, Nebraska White Prize, during a six-year period, 
indicate that long, slender, smooth seed ears with a relatively 
short and flinty kernel excelled large, rough, deep, and starchy 
grained seed ears by 9 per cent and the original unselected corn 
by 1.4 per cent. In another six-year test with standard Iveid’s 
^ ellow Dent in which continuous selection was practiced, the 
long, smooth type of ears surpassed the standard medium, rough 
type 7 per cent. In a two-year test with local Hogue’s Yellow 
Dent corn, long, slender ears with a rather smooth, shallow 
kernel excelled ears with deep, rough kernels 9 per cent and the 
original corn «S per cent in yield of grain. While complete notes 
descriptive of the plant development resulting from these ear 
