250 



SPOROPHYTE OF RICCIOCARPUS 



rather cubical and densely granular. The growth and division 

 of the granular cells continues until about 400 have been formed, 

 when they round off, become separated from one another and 

 increase greatly in size (Fig. 183, C) . These large cells, called 

 spore mother cells, form four spores each, as in the tetraspores 



FIG. 183. Germination of the gametospore : A, basal portion of an 

 archegonium, showing the germinating gametospore in the four-cell stage. 

 B, later growth, forming a capsule with wall cells, w, which inclose ]arge 

 granular cells. C, a portion of the capsule, showing spore mother cells 

 rounding off and floating in the fluid of the capsule. D, the mother cells 

 dividing and forming four spores each. H. O. Hanson. 



of the re/i algae (Fig. 183, D). The delicate walls of the cap- 

 sule break down as soon as the spores are matured, leaving them 

 free in the archegonium, and later they are set free by the decay 

 of the latter organ. These spores in some forms are provided 

 with thick walls and are, therefore, resting spores adapted to 



