GENERAL MORPHOLOGY 437 
and fourteen fertile spikes. Of 70 specimens examined in Kew and the 
British Museum, ranging from those with a single sterile lobe to eleven, 
and from one fertile spike to seventeen, the totals came out as follows : 
Specimens observed, 70 
Sterile lobes, 328 
Fertile spikes, - 373 
When these figures are taken together with observation of special cases 
as illustrated in the drawings, they demonstrate a substantial parallelism 
between the number of sterile lobes and of fertile spikes, though this 
parallelism cannot be pursued into exact numerical detail. It is plain, 
also, as illustrated by the above figures, that the leaves with most lobes 
are those which are broadest and have the largest assimilating surface ; 
thus, speaking generally, the number of fertile spikes increases with the 
increasing leaf-area. 
It has already been pointed out that spikes in a truly marginal position are 
rare; they do, however, occur, and Fig. 238 H shows one, together with its 
vascular connection with the marginal bundle of the sterile frond. The 
individual spikes correspond in form and general structure to the single 
spike of O. vudgatum. But many of them show various stages of branching. 
The following drawings (Fig. 239) illustrate such steps as may be seen 
in Ophioglossum palmatum: In Fig. 239 a are two spikes, each with an 
imperfect lateral branch, but in both the series of sporangia is continuous 
over the lateral: protuberance. At the apex of each of the spikes of 
Fig. 239 D is an indication of branching of the same nature. The branching 
may be more elaborate, as in Fig. 239 B, where there are three borne upon 
one stalk, the series of sporangia along the margins of them all being 
interrupted, while it may also be noted that the vascular bundles are 
united below in the common stalk. But in other cases the series of 
sporangia may be interrupted (Fig. 239 c), so that the two branches now 
appear as two distinct spikes seated upon a common stalk, though the 
central vascular bundles unite below into a common bundle before their 
insertion on the vascular system of the sterile frond. Figs. 239 p and E are 
substantially similar, but show a more complete separation of the vascular 
supply for the two spikes; while Fig. 239 F shows two spikes in which the 
stalks are completely separate to the base, though the two are inserted 
close to one another, and in the same relative positions as the branches 
in Figs. 239 c, D, and E. 
The above series thus illustrate successive stages leading up to complete 
branching of the fertile frond. It has been suggested by Bitter’ that the 
simpler examples are really young plants of O. pa/matum, and it seems 
not improbable that this may actually be the case, and the progression 
be illustrated in the advancing life of the individual. However that may 
be, it is by comparison of O. pendulum and of abnormal cases of 
1Engler and Prantl, i., iv., p. 456. 
