214 
Bower . — Ophioglossum simplex , Ridley . 
happen to the subtending leaf. As supporting this theory there is the fact 
of mycorhiza in the root. We have at present no means of measuring 
from mere structural evidence the nutritive powers of mycorhizal roots, 
or how far in any given case they may supplement or supersede the 
chlorophyll-nutrition. In proportion as the mycorhiza is more effective 
a reduction of the assimilatory system may be anticipated, such as our 
theory demands, while the spore-producing parts would retain their dimen- 
sions, provided that the efficiency of nutrition be not diminished 1 . A second 
point is the habitat, which Mr. Ridley specially describes as £ dense wet 
forests,’ and pointedly compares it with the c open grassy spots ’ where 
other ground-growing Ophioglossums are found. This seems to throw 
the onus of nutrition upon the mycorhizal roots. Applying these con- 
siderations to our present case, it is physiologically possible to contemplate 
a reduction, or even a complete abortion, of the sterile lamina to such 
a condition as that shown in O. simplex. 
And here the anatomical evidence detailed above will come in. It has 
been above pointed out that the upper part of the appendage in O. simplex 
shows structure as well as form characteristic of the Ophioglossaceous 
spike; also that towards the base the structure is comparable with that 
found at the leaf-base in O. pendirium , while the insertion of the vascular 
supply upon that of the axis is characteristic of the leaf of that same 
species : thus the structural evidence falls in with a theory of abortion 
of the sterile lamina. This, however, presumes that there is a transition 
from spike to leaf-stalk as the length of this apparently undifferentiated 
stalk is traversed. Any theoretical difficulty which such a presumption 
may occasion will be relieved by comparison of the case of the stamina 1 
flowers in the genus Euphorbia : there the transition from floral axis to 
filament (a transition which is not less essential than that from spike 
to leaf-stalk) is only marked in the slightest way by the well-known 
articulation. In both cases, on the view above put forward, the simple 
condition has been arrived at by a process of abortion. 
Of the two explanations of O. simplex thus put forward, I am disposed 
to prefer the second, but in all the circumstances of this peculiar case it is 
not possible to come to any certain conclusion, one way or the other. 
This can only be done when more material shall be available. Meanwhile 
the case cannot be held to invalidate the view of Celakovsky, so far as 
to dictate its rejection. 
The systematic position of O. simplex will be, according to the charac- 
ters above described, in Prantl’s § Ophioderma. But while accepting Prantl’s 
division of the genus (1. c., p. 299), it would I think be well to add 
to the diagnosis the fact that the insertion of the leaf-trace differs in 
§ Ophioderma from that in § Eu ophioglossum. In all species of the latter 
1 Phil. Trans. T903, vol. cxcvi, pp. 228 and 233-4. 
