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 Sweet Com showing 

 the absorption of the endosperm bv the the effect of the pollen 



embryo or obscured by coverings. It is in °!J^"°7 ^^'^^ ^°™- 

 ,, X . J. 1 • >i 1 The plump kernels 



the Grass type of seeds, as m Corn where j^^^g endosperm hke 



the endosperm remains outside of the em- the Yellow Dent Com, 



bryo and can be seen through the pericarp, due to the influence of 



that the influence of the sperm on the the sperm which fused 



endosperm and known as xenia is often with the primary endo- 



i- 1 1 -ivT j^- J^^ n r^ i_ sperm nucleus. After 



noticeable. Notice the ear oi uorn shown ^ j ^gb^er 



in Figure 57. This was an ear of Sweet 

 Corn which was partly pollinated with pollen from hard Field 

 Corn. Notice the kernels which have the hard plump endo- 

 sperm and resemble the kernels of Field Corn. In the de- 



FiG. 57. — An ear of 



