XI 



L&PTOSPOKANGIATM HETEROSPOREJE 



in 



F. ; 



FIG. 240. Azolla -filiculoides. A, Vertical longitudinal section of the stem apex, X6oo; 

 r, mother cell of a root; B, three successive transverse sections just back of the 

 apex; m, the median wall; L, mother cell of a leaf, X6oo; C, single lobe of a 

 young sterile leaf, X6oo; D, fertile leaf segments with two very young sporocarp 

 rudiments, X6oo; E, longitudinal section of young macrosporangium, showing the 

 young indusium (id), X6oo; t, first tapetal cell; F, older macrosporangium com- 

 pletely surrounded by the indusium, Xsso; n, Anabccna filaments. 



