128 THE "CLUB-MOSS." 



rangium had developed so as to form a firm covering for 

 the gametophyte and embryo, we should have a seed, the 

 characteristic structure of the next great group. 1 



It is by no means certain that seed-plants originated 

 from ancestors like Selaginetta. Nevertheless the resem- 

 blance between it and the great group, Angiosperms, is 

 striking and too significant to be overlooked. 



1 Examine text illustrations of Selaginella, and also those by Miss 

 Florence M. Lyon on "A Study of the Sporangia and Gametophytes of 

 Selaginella apus and Selaginella rupestris," Bot. Gaz. 32 : 124 and 170. 



