Hayes and Garber - Cucurbit Breeding

MAIZE BREEDING 183
in the endosperm and a correspondingly large proportion of
corneous starch. Some seeds may be entirely free from soft
starch, but there is generally some soft starch surrounding, the
germ. The group is characterized by the small size of its seeds
and ears.
Zea mays indentata, the dent corns. Sturtevant, Bulletin
Torrey Botanical Club, 1894, page 329.
The corneous starch in this group is located at the sides of the
seed and the soft starch extends to the summit. The soft
starch dries more rapidly than the corneous and this produces
the shrinkage which causes the characteristic indentation of the
seed.
Zea mays amylacea, the soft or flour corns, Sturtevant, Bulletin
Torrey Botanical Club, 1894, page 331.
This group is recognized by an almost entire absence of corneous
starch. There is no indentation in some varieties and only
a slight one in others. The soft starch content characterizes
this group.
Zea mays saccharata, the sweet corns. Sturtevant, Bulletin
Torrey Botanical Club, 1894, page 333.
"A well-defined species group characterized by the translucent,
horny appearance
of the kernels and their more or less
crinkled, wrinkled, or shriveled condition." East (1910d) presented
evidence which shows that the sweet corns are dent, flint,
or pop varieties which have not the ability to mature starch normally.
The few starch grains produced are small, angular, and
imperfect.
INHERITANCE OF CHARACTERS
Endosperm Characters. The word xenia was first used by
Focke (1881) to denote the effect which was apparently produced
by the action of pollen upon the maternal tissue of the seed.
The endosperm of maize was cited as a classical example of such
an effect.
After the discovery by Guignard (1899) and Nawaschin
(1898) that the polar nuclei of the endosperm fuse with the
second male nucleus of the pollen grain, De Vries (1899), Correns
(1899), Webber (1900), and Guignard (1899, 1901) saw that this
furnished an explanation of xenia in maize. From a consideration
of inheritance of endosperm character the following law of
xenia may be formulated :