Ophioglossum (C heir og loss a) palmatum , L. 283 
that the early stages are substantially similar to those described for the 
Adder’s Tongue (Figs. 13, 14). 
As regards position upon the leaf, the lowest spike is as a rule median, 
though this is not without exception, as is seen in mature specimens (Fig. 7 
also, ‘ Land Flora’, Fig. 238 , d). In the younger of the two fertile leaves 
observed the lowest spike was perfectly median (Fig. 14). Passing upwards, 
younger spikes in the first stage of initiation were seen right and left, but 
they were distinctly intramarginal as regards the external contours (Fig. 13). 
It thus appears that there is an acropetal succession in the origin of these 
intramarginal spikes, and it is possible that the succession here seen might 
have been continued further had the development of the leaf been more 
advanced. 
In the older fertile leaf the number of spikes was greater. Figs. 7-10 
represent sections successively at higher levels. The lowest (Fig. 7) shows 
a single median spike as before. Higher up indications of at least four 
other spikes are seen (Figs. 8, 9) ; they are disposed right and left of the 
median line, but all are distinctly intramarginal so far as the external form 
is concerned. One of these is represented on a larger scale in Fig. 15, and 
the spike appears seated at a considerable distance from the margin. It 
may be added that, following up the region of greatest curvature in this 
section into the upper region of the leaf, it is found to be continuous with 
that marginal segmentation already described (Figs. 11, 12). One further 
point is worthy of note : that in Fig. 8, on the left-hand side, the section, 
though it is in a transverse plane, traverses two spikes. They are both 
intramarginal, but one more deeply than the other. In Fig. 16 three such 
spikes are traversed in the single transverse section. Here the group in 
question lay near to the middle of the adaxial face. In point of origin it 
seems impossible to refer such developments, varying as they do in degree 
of intramarginal insertion, to the margin of the leaf. The plain fact is that, 
whatever the vascular connexions may be, the spikes of O. palmatum are in 
their prime origin intramarginal. 
The later phases of the discussion on the morphological nature of the 
fertile spikes in Ophioglossum palmatum have turned so largely upon the 
anatomical facts that, while not neglecting other data, it is necessary at 
the start to be clear as to the vascular connexions. It is common knowledge 
that the leaf-trace in Helminthostachys , Botrychium , and E u- Ophioglossum 
leaves the stele as a single strand. Already Holle 1 had shown that while 
in Botrychium that strand divides into two equal parts, in Eu-Ophioglossum 
there is a central strand which maintains its identity between the lateral 
strands which spring from it, even up to the apex of the blade. 2 The 
lateral strands vary in number in the different species. 
1 Bot. Zeit., 1875, p. 269. 
2 See also Prantl, System der Ophioglosseen, PI. VII, VIII. 
