XIX] 



DEVELOPMENT OF SPIKE 



Fig. 366. Ophioglossutn {Ophioderma) pen- 

 dulum L. A, transverse section of spike 

 showing the sporangiogenic band cut trans- 

 versely; B, longitudinal section following 

 its length, and showing it already differ- 

 entiated, with separate sporogenous groups; 

 C tangential section of a spike of like age, 

 also showing two sporogenous groups. 



(XIOO.) 



1 ij,. .si>,. Opiiioglossuin (Ophiodcnua) pcnditlitiii L. A, />', transverse scclitiu.-, of .^pikc.-. ul diltcicni 

 ages to show sporangia and vascular bundles, slightly enlarged. C, a single sporangium older than 

 in Fig. 3665, in radial longitudinal section : the tapetum lightly shaded surrounds the darker sporo- 

 genous mass ; Z>, tangential section of like age, showing one sporogenous mass darkly shaded : the 

 smaller shaded groups will form the vascular strands ; E, part of a transverse section of an older 

 sporangium of O. reticulatiiin. ( x 100.) 



