916 



VII. ISOETE^). 



Jsoetes. Trausvcrse section of rhizome. 



Jtoetei. Transverse section of the bases of 



fronds, showing the arrangement of the 



<? and 9 sporangia (mag.). 



J. telacra. 



Transverse section of a sporangium, 

 enclosing anthuridia (mag.). 



JtoeUs 



1. ittacea. Macrospores (mag.). Jtoetet. Alicrosporcs (mag.). 



/. setacea. 



Vertical section of a 



sporangium, enclosing 



antheridia (mag.). 



/. setacea. 



PhyUopode with doable 

 ligule, sporangium con- 

 taining antheridia. 



/. lacustris. 



9 phyllopode, showing the 



young sporangium and 



the ligule. 



J. lacustris. 



9 phyllopode, showing the 



sporangium open and 



deprived of spores. 



