THE DEVELOPMENT OF SEXUALITY IN PLANTS 175 



gives rise to gametes of two different sexes, is known as the gameto- 

 phyte. The latter generation is the conspicuous green plant that 

 manufactures food and serves as host for the sporophyte generation 

 which is permanently attached to it. 



The gametophyte of the simple moss, Funaria hygrometrica, is a 

 short upright stalk bearing usually three spiral rows of simple leaves, 



sperm 



embryo 



Sfertili^ect egg 



rontheridiunz. 



mum. 



dbcmetophone , 



\ 



bud 



protonemol 

 threocC 



ycrunS gb-metophyt' 



The life cycle of Funaria, a moss. Which stage is more prominent, 

 gametophyte or sporophyte? 



each containing numerous chloroplasts. At the lower end, a group of 

 small brown rkizoids furnish the means of attachment to the sub- 

 stratum. The moss plant is dioecious, having separate sex organs 

 on different plants. The male gametophytes are shorter than the 

 female gametophytes and bear at the upper tip a cluster of structures 

 known as antheridia. Each mature antheridium looks like a tiny 

 club with a wall formed of rather large, thin cells, which forms a recep- 

 tacle for numerous motile sperm cells. The female gametophyte 

 bears at the apex of the short stem, although in the mature plant 



