208 



CRYPTOGAMS 



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

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



353. Selaginella. 



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

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



the smaller {micro sporangia, mi) con- 

 tain large numbers of very much 

 smaller microspores. Macrosporangia 

 are found only in lower axils, or else 

 only in axils on one side of the spike. 

 Leaves with which 

 sporangia occur, as 

 here, are termed 

 sporophylls. 



486. In the af- 355. 

 ter development of 

 the spores Selagi- 

 nella departs in a 

 354. Fruiting spike of remarkable man- 

 ner from the Ferns. The spores of 

 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 within the original spore walls. Moreover, the nature 

 of these internal formations is different in the two kinds 



ma.- 



Sectiou of micro- 

 spore: s, cells 

 in which an- 

 therozoids ori- 

 ginate ; p, pro- 

 thallial cell. 



Fruiting spike of 

 Selaginella (/), 

 and the same in 

 section magni- 

 fied : ma, macro- 

 sporangium ; mi, 

 microsporangium. 



— GOEBEL. 



