ANTHERS AND MALE GAMETOPHYTE 337 



the ovule that makes possible the seed. When the en- 

 closed and parasitic female gametophyte is full-grown it 

 consists of only seven cells. At one end is the egg cell 

 and two associated cells; at the opposite end are three 

 vegetative cells which ordinarily are of negligible value; 

 in the middle is a single large nucleus which was formed 

 by the fusion of two, one of which came from the egg 

 group at one end and the other of which came from the 



B 



B, a single ovule showing the outer coverings or integuments 

 and the female gametophyte in the middle. The latter shows in 

 this single section only 4 of the seven cells actually present. 



opposite group of vegetative cells. This single large 

 double nucleus is called the primary endosperm nucleus. 

 It plays a very important part in the development of 

 certain seeds of economic value and must be fully under- 

 stood here if what is to be said later in respect to certain 

 phases of heredity in corn is to be understood. 



The Anthers and Male Gametophyte (Fig. 91). — 

 Turning our attention now to the anthers it will be found 



