TO Nebraska Agricultural Exp. Station, Research Bui. W 
same degree, but are the reciprocal of each other. Class 3 a has 
probably actually had somewhat broader breeding than 3 b , be- 
cause the full number of ears for continuing 3 b has not always 
materialized, thereby lowering the relative number of plants 
represented in the continuation of the strain. 
4. Broad breeding within an ear-to-row strain, in which the 
seed is continued each year with a composite of ears from 15 
plants, fertilized with composite pollen from 15 sister plants of 
the same strain. 
5. Crossbreeding between ear-to-row strains, in which sev- 
eral strains are planted in alternating rows and cross-fertilized 
by detasseling part of them, seed being selected from the de- 
tasseled rows. 
6. Ordinary wind fertilization within a commercial variety, 
in which the seed is continued each year with a composite sam- 
ple of a large number of well-developed ears. 
7. Crossing of varieties , in which two commercial varieties 
are planted each year in alternating plats, one of which is de- 
tasseled to furnish the hybrid seed. 
DEGREES OF INBREEDING, HOGUE’S YELLOW DENT CORN 
Five of these degrees of inbreeding, which have just been 
described, viz, No. 1, 3 a , 4, 5, and 6, have been continuously car- 
ried on with Hogue’s Yellow Dent corn since 1909. Classes 1 
and 3 a were begun in 1909 with each of three ear-to-row strains, 
selected from each of four high yielding strains, having their 
origin in an ear-to-row test begun in 1906. The original strains 
are the same as those described on page 48 as the foundation 
stock of Hogue’s Yellow Dent pure lines. Classes 4 and 5 
originated in 1909 from the four highest yielding individual 
ear-to-row strains selected in 1903. Class 6 merely represents 
the original wind fertilized variety, seed of which was obtained 
each year prior to 1910 from R. Hogue, living at a distance of 
30 miles from the Station. Since 1910 it has been continued an- 
nually in large seed plats at the Nebraska Experiment Station. 
The yields have been determined for the various strains 
of any one degree in composite, rather than individually. Seven 
years’ results are given in Table 25. The five degrees of in- 
breeding — 1, 3\ 4, 5, and 6 — yielded respectively 16.8, 42.2, 49.2, 
54.0, and 53.1 bushels per acre. Every degree narrower than 
that of crossing between ear-to-row strains resulted in a reduc- 
tion of yield. The more nearly the fertilization approached 
self-fertilization, the greater the reduction. 
