96 



THE OPHIOGLOSSALES 



case is shown in fig. 82, Ej where the lamina is almost entirely suppressed and the 

 terminal character of the spike is very evident. 



As the leaf develops, there is a very great increase in size in the lamina, which, 

 as we have seen, may reach a great length. The anatomical structure of the leaf 



Fig. 64.- 



A. Section of stem apex. X3. 



B. Young sporophyll. jp, sporangiophore. X35. 



C. Stem apex, Xy and youngest leaf, /. 



-OphiogJossum pendulum. 



D. The stem apex, more enlarged. 



E. Very young sporophyll. sp^ sporangiophore. 



F. Cross-section of young sporangiophore. 



X90. 



closely resembles that of Euophioglossum, but the stomata are much larger and 

 around the stoma is a concentrically arranged series of cells, indicating that probably 

 the formation of the mother cell of the stoma is preceded by a series of preliminary 



Fig. 65. — Vascular bundle from petiole of Ophioglos- 

 sum pendulum. 



Fig. 66. 



A. Section of petiole of a sporophyll of 0. pendulum. 



B. Section near base of lamina, sp, base of spike. 



C-E. Sections of peduncle of spike. C and D are from the 

 same leaf; E from a laiger one. 



divisions in the epidermal cell. The tissues in the petiole are veiy like those in the 

 lamina of the leaf except that they are somewhat more compact. The walls of the 

 ground tissue in this region are very deeply pitted. 



The structure of the vascular bundle of the petiole (fig. 65), is much like that in 

 Euophioglossum, except that there is a rather greater development of tissue upon the 



