22 



VASCULAR CRYPTOGAMS 



The spores are of two kinds, one of which is many hundred times 

 larger than the other. The larger spores, or megaspores, produced in 

 megasporangeS) are female ; the smaller spores, or microstores, produced 



F/G. 5. Pihila ria globulifera. L., with FIG. 6. Marsilea quadrifolia L., with fructifi- 

 fructification, natural size. (After cation, natural size, and fructification en- 



Luerssen.) larged. (After Luerssen.) 



in microsporanges, are male. The megaspore is not completely spherical, 

 but has a distinct apical protuberance, which at the period of maturity 

 is enveloped in a thick firm layer termed the epispore, formed by the 



