SEED COAT 



469 



phytic tissue in the seeds of Angiosperms comparable to that 

 in the seeds of Gymnosperms. The endosperm in the seeds of 

 Gymnosperms is simply the portion of the gametophyte that 



FIG. 414. The life cycle of Angiosperms illustrated by the life cycle of 

 Red Clover. At the left in the line above, a branch of Red Clover with 

 heads of flowers (X ); next, a vertical section through a flower, showing the 

 floral structures; at the right, a section of an anther, a pollen grain, and a 

 pollen grain with tube and male gametophyte developed. At the left in the 

 line below, an ovule with female gametophyte mature and pollen tubes en- 

 tering through the micropyle; next, embryo and endosperm forming; next, 

 seed mature from the embryo of which the new plant at the right develops. 



remains, but in Angiosperms the endosperm develops after the 

 gametophyte is formed and from a nucleus formed by the fusion 

 of three other nuclei, one of which came from the male gameto- 

 phyte. 



