164 



Introduction to Botany. 



reproductive cell is much larger than the other, is stored 

 with food materials, and is stationary, while the smaller re- 



productive cell is motile, seeks 

 the larger cell, and fuses with 

 it. The larger cell may there- 

 fore be designated the female 

 reproductive cell or egg, and 

 the smaller cell the male repro- 

 ductive cell or sperm. 



119. Functions and Relation- 

 ships of Floral Structures. - 

 The essential parts of a flower 

 consist of the sperms and the 

 eggs, and the organs which 

 bear and protect them. Figure 

 87 is a diagrammatic represen- 

 tation of a typical flower. At 

 b is a sepal, one of the external 

 members of the flower, which 

 taken collectively constitute 

 the calyx. The calyx enwraps 



Reproduction in Oedogomum ctha- J 



turn, i, a, an oogonium in which is the Other parts of the flower 



borne the large egg cell; b, an an- . fa bud and iyes them SQme 

 thendium in which the sperm cell 



occurs; 2, showing the sperm cell degree of protection, and some- 



$t&5riZ3z. times '* is brightl y colored and 



ing the protoplasts in two ceils of an helps to make the flower con- 



Oedoeonium filament ready to T , 



It IS not 



emerge and become asexual swarm SplCUOUS. 



spores; 4, an asexual swarm spore. fjO the production of seeds, and 



After PRINGSHEIM. . . , . 



is sometimes wanting. 



At c is a petal. The petals constitute the corolla ; they 

 are usually white or brightly colored ; in the bud they 

 enwrap the inner members and thus help to protect them, 

 and in the open flower they are advertisements to insects, 



