IX 



MA RA TTIA CEyE—ISOE TA CE^ 



275 



Filicinea:, although it must be understood that this is 

 provisional. 



Fig. 144. — A, Plant of Isoetes Bolandcri (Eng\m), X i ; B, base of a leaf with niacrosporangium, X4 ; 



/, ligula ; 7', velum. 



Isoetes has been the subject of repeated investigation, 

 Hofmeister ^ being the first to study its development in detail. 



^ Hofmeister (i). 



