232 Plants and their Ways in South Africa 



two kinds of sexual organs, resembling those in the liverwort 

 and the moss. Archegonia containing the germ- or egg-cells 

 are near the notch in the prothallium ; antheridia containing 

 the sperm-cells are down near the point among the rhizoids. 

 A sperm-cell swims into the archegonium, unites with the 

 germ-cell, and then the germ-cell grows into a leafy fern 

 plant, just as the stalked capsule of the moss grew out of the 

 pockets hidden among the leaves. The fern plant, though, 

 forms roots and can soon take care of itself, 

 while the moss capsule always depends upon 

 the leafy part for its food. In the liverworts, 

 mosses, and ferns, the germ-cell has to swim 

 to reach its sperm-cell, but the spores are 

 borne up into the air, and are scattered by 

 the wind. 



In the ferns and all more highly developed plants, 

 the sporophyte is the conspicuous leafy generation. 



I- 11. 



Fig. 206.— I. Kmo%%T^\^.x\i{Bryum argenteum). II. Capsule enlarged. III. 

 Capsule open for the spores to escape. (From Thom6 and Bennett's " Struc- 

 tural and Physiological Botany ".) 



The higher plants also have two generations, but the generation corre- 

 sponding to the prothallium of the fern is hidden away, partly within the 

 seed and partly within the pollen grains. The sperm-cells are contained 

 in the pollen, and are carried down in the pollen-tube. By this time they 

 have lost the power of swimming. 



Osmunda regalis, L. is a stately fern also extending across 

 South Africa. The fruit-bearing part is quite distinct from the 

 leafy part, forming a plume-like panicle. 



Schizea pectinata, Sm. is a curious fern, which might 



