208 



CRYPTOGAMS 



leaf axils in the terminal "fruiting spikes" (Fig. 354). 

 They are of two kinds as concerns contents, and often as 





353. Selacfiuella. 



concerns size and color. The larger (macrosporangia, ma, 

 Vig. 354) each contain four large spores, or macrospores ; 

 the smaller (microsporatiffia, mi) con- 

 tain large numbers of very much 

 smaller microspores. iMacrosporangia 

 are found only in lower axils, or else 

 only in axils on one side of the spike. 

 Leaves with which 



ma.. 



sporangia occur, as 

 here, are termed 

 sporojihylls. 



486. In the af- 

 ter development of 

 the spores Selagi- 

 nella departs in a 

 I'emarkable man- 

 ner from the P^erns. 

 Ferns give rise to distinct structures 

 (prothallia) upon which archegonia 

 and antheridia are produced. In 

 Selaginella the germination of the 

 spore goes no farther than the formation of a number of 

 cells ii'itliiii the oriijinal spore walls. Moreover, the nature 

 of tliese internal formations is different in the two kinds 



Fruiting spike of 

 Selaginella (/), 

 aiifl tlie same in 

 s e I' t i o n magni- 

 fied ; irm, macro- 

 sporangium : nt>, 

 raicrosporangium. 



— GOEBEL. 



355. Section of micro- 

 spore: .■:, cells 

 in wliich an- 

 therozoids ori- 

 ginate; /), pro- 

 thallial cell. 



The spores of 



