C orn In vestigations 
43 
PRODUCTION OF ELEMENTAL STRAINS 
Two standard eastern Nebraska varieties of corn were used, 
Hogue’s Yellow Dent and Nebraska White Prize. Inbreeding 
work with the former variety began in 1908 and with the latter 
in 1912. Ear-to-row strains were used as the foundation stock. 
TECHNIQUE OF ARTIFICIAL POLLINATION 
The procedure in self-fertilization is to pollinate the silks 
of an ear with pollen produced by the tassel of the same plant. 
To accomplish this without contamination by foreign pollen, 
good quality manilla paper bags are inverted over the tassel and 
tied at its base a few clays before the pollen is expected to be 
used, which usually is about the time when the tassel begins to 
shed pollen. This frequently is facilitated by removing the 
upper leaf. The enclosing of leaves in the bag is avoided, as 
the moisture accompanying transpiration may cause deteriora- 
tion of the pollen. Whenever the ear shoot has made considera- 
ble growth, but a few days before the silks emerge, a paper bag 
Fig. 8. — Inbreeding and crossbreeding pure lines of Hogue’s Yellow Dent 
corn. The corn in this illustration may be compared for size with 
the original Hogue’s Yellow Dent corn in figure 7, from which it 
was derived by six years of inbreeding. 
