232 



PLANT LIFE. 



Spores, and much sinallcr ones, known rs microspores (fig. 

 241). Each kind, when it germinates, iirodures a sexual 

 pkmt, or gametoph\lc (^| 37 7), npon which, however, only 



F.r.. 255. 



Fir, 



Fig. 235. — Part of two sjiorophytes of a horsetail { F.,]7i Iscttim nr-M-nst-). A, the 

 spring shoots, with sheatli-Ht:e wliorls of lea\'es below and crowded sporophylls abo\e 

 /,', summer shoots, much brauctied, witll inconspicuous ica\'es ; iuitriti\'e work all 

 done by stems of these shoots. Two thirds natural size. — ,-\ftcr Kerner. 



Fk;. 236. — Three sporophylls from tlie flower of a horsetail < J\!/?/ iscttmi tcl'inifriii), 

 seen in different positions, .v, the shield-shaped sporoplivll : .v/, its stalk attached to 

 the center of dorsal face ; .vv, sporangia. Magnified aliout u, diam. — .\fter Sachs. 



one sort of sexual organs is borne. The niegaspores gi\"e rise 

 to plants bearing female organs onlv, the microspores to 



