18 Chrysler.—Nature of the Fertite Spike in the Ophioglossaceae. 
Fig. 2i. Marsilia quadrifolia. Transverse section through petiole, showing the mode of origin 
of the strand which supplies the sporocarp. This strand appears at the left, and is enclosed in dense 
sclerenchyma. x 90. 
Fig. 22. Helminthostachys zeylanica. Transverse section through petiole of a young specimen. 
The odd strand in the upper part of the figure arises from the strand at its right and supplies the 
fertile spike, the base of which is visible as a ridge on the surface of the petiole, x 30. 
PLATE II. 
Fig. 23. Aneimia tomentosa , Swartz, var .fulva Hook and Bak. Introduced for comparison. 
Fig. 24. Botrychiiwi obliquum , Muhl. Specimen with a pair of fertile spikes. 
Fig. 25. Same. Specimen with one fertile pinna in the sterile segment. This pinna is really 
lateral, but has been bent upward in pressing the plant. 
Fig. 26. Same. Specimen with a pair of fertile spikes in addition to the ordinary one, which 
is seen to be inserted further down than the pair. 
Fig. 27. Same. Specimen with an extra fertile spike, which in this case represents a single pinna. 
Fig. 28. Same. Specimen with two fertile spikes partly fused. 
