282 Bower. — Notes on the Morphology of 
that of 0 . palmatum* The attachment of the roots is essentially the same. 
A difference of some importance is, however, seen in the leaf-trace. Whereas 
in Hehninthostachys , Botrychium , and Eu-Ophioglossum the trace consists of 
a single strand springing from the base of the foliar gap, here there are two 
strands which originate widely apart, and laterally from the edges of the 
foliar gap. The leaf-trace thus divided is found also in O. pendulum and 
simplex} It has already been pointed out that these species, all of which 
are of saprophytic tendency, may be regarded as specialized offshoots of 
the Ophioglossaceous stock. And just as in the Ferns the single strand is 
characteristic of those types which may be held to be more primitive, while 
the divided leaf-trace is probably a derivative condition, so also here the 
condition seen in Eu-Ophioglossum and others of the family is probably the 
primitive state. This conclusion should have its bearing on the compara- 
tive study of the fertile spikes in those representatives of the genus. It 
should dispose us to inquire whether the elaboration of the spikes which is 
seen among them is not also derivative as compared with the simpler 
condition of Eu-Ophioglossum. 
Morphology of the Fertile Spikes in O. palmatum. 
Hitherto the development of the spike of Ophioglossum palmatum has 
never been described. Fortunately the terminal bud of the large plant 
under investigation provided two young leaves which were developing as 
fertile leaves, and gave the opportunity for observing early stages of the 
spike as seen in transverse sections of the blade (Figs. 7-10). This has 
a semilunar outline, with relatively blunt margins which are unequal, one 
being habitually more massive than the other. The cell cleavages at the 
margin are of the T-type, and are repeated often with some degree of 
regularity at the point of greatest convexity. The result is a characteristic 
cell-net such as is shown in Figs. 11, 12. But this structure is most clearly 
seen in sections of the lamina above the insertion of the spikes. Lower 
down, where the margin is more rounded, the T-division still holds, 
but not being repeated in rapid succession the structure appears less 
characteristic. 
It is naturally impossible to give any exact account of the segmenta- 
tions involved in the origin of the spike from two leaves only, and both 
of them cut in transverse section. But as the details are fairly well known 
for O. vulgatum , this species will serve as a basis for comparison of the less 
perfect data from O. palmatum? The spike arises as an outgrowth in 
which several cells appear ta take part (Fig. 13). As the convexity 
increases, segmentation is seen which is compatible with the type described 
for O. vulgatuin, having an initial cell with the shape of a four-sided 
pyramid. A comparison of the drawings, meagre though they are, indicates 
1 Ann. of Bot., 1904, p. 205. 2 Compare Land Flora, pp. 447-8, Fig. 246. 
