THE RESULTS OF POLLINATION 
51 
The effect of fertilization in reference to the influence which 
the sperms have upon the character of the endosperm of the seed 
and upon the character of the plant which 
the embryo of the seed will produce is a sub- 
ject receiving much attention in plant-breed- 
ing. The endosperm nucleus consists of a 
sperm and a primary endosperm nucleus, 
each of which is capable of determining the 
character of the endosperm. Likewise, in 
the fertilized egg, the contents of both sperm 
and egg are capable of determining the 
characteristics of the plant developing from 
the fertilized egg. But the influence of 
the sperm is toward the production of both 
endosperm and plants having the features 
which are characteristic of the pollen parent, 
while the egg and primary endosperm 
nucleus tend to reproduce in the offspring 
those features characteristic of the mother 
plant. Thus it follows that if the pollen 
parent is very different from the mother 
plant, as is the case when the parents be- 
long to different varieties or species, there 
will be opposing tendencies in the fertilized 
egg and endosperm nucleus. Such a fertil- 
ized egg develops into a plant known as a 
hybrid. The hybrid character of the endo- 
sperm in most seeds is either lost through 
the absorption of the endosperm by the 
embryo or obscured by coverings. It is in 
the Grass type of seeds, as in Corn where 
the endosperm remains outside of the em- 
bryo and can be seen through the pericarp, 
that the influence of the sperm on the 
endosperm and known as zenia is often 
noticeable. Notice the ear of Corn shown 
in Figure 57. This was an ear of Sweet 
ry 
PTAE 21 
Le 
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z t 
Fen pe 
7 
fey 
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=ae 
Greer 
fEa99p 
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es 
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a 
Fic. 57.— An ear of 
Sweet Corn showing 
the effect of the pollen 
of Yellow Dent Corn. 
The plump kernels 
have endosperm like 
the Yellow Dent Corn, 
due to the influence of 
the sperm which fused 
with the primary endo- 
sperm nucleus. After 
H. J. Webber. 
Corn which was partly pollinated with pollen from hard Field 
Corn. 
sperm and resemble the kernels of Field Corn. 
Notice the kernels which have the hard plump endo- 
In the de- 
