[Chap. XLIX FERNS, CLUB MOSSES AND EQUISETUMS 



671 



Fig. 316. Three species of Lijcopodiian: A, L. complanatiim with gametophyte 

 (after Bruchmann); B, L. lucidulum with sporangium (bi) and vegetative 

 propagules (b.); C, L. clavatum with gametophyte (Ci). 



The relative size of the two kinds of spores is perhaps insignificant, 

 for in equisetums the spores are indistinguishable, and in some seed 

 plants the microspores are larger than the megaspores. The significant 

 fact is that in Selaginella the gametophvtes resulting from the germina- 

 tion of the spores bear either archegonia or antheridia, but not both. A 

 thallus producing only one kind of gamete is unisexual: one producing 

 both kinds is bisexual. 



