20 MR. C. E. JONES ON THE MORPHOLOGY 
mucilage and the mesophyll-cells are not well provided with intercellular spaces. A 
fungus was found permeating the tissues very generally, but there was no reason to 
suppose that this was regularly present. 
L. annotinum shows very distinctly a feature which ocdurs in many of the Lycopods, 
i. e. the peculiar thickenings and pittings in the walls of the mesophyll-cells, and, generally 
speaking, striations and pittings are particularly noticeable upon the walls of all cells of 
Lycopods. The appearance presented in the loose cells of the leaf-base, as seen in the 
surface view (figs. 12 and 13), is that of oval plates marked with very definite pits. Some 
of the pits are very large, others much smaller. The whole appearance is that of a 
magnified sieve-area. In section (fig. 12) it is found that these plates represent thicker 
portions of the wall, and whereas there are ordinary pits which correspond on the two 
sides, there are also depressions which occur on one side only, and the larger pits in 
surface view correspond to these. 
LYCOPODIUM COMPLANATUM, Linn. ; L. CHANMJECYPARISSUS, A. Br. ; L. ALPINUM, Linn. 
It is convenient to take these three forms together. In the first place, Mr. J. G. Baker, 
in his * Fern Allies,’ unites L. Chamecyparissus as a variety with L. complanatum, and 
these two are included in the small category of Lycopods which have dimorphic leaves, 
an interesting group suggestive of Selaginella. It would not be expected, therefore, that 
it would be difficult to distinguish Z. alpinum, which is placed in the clavatum section, 
from the others, as there should be a difference both in the leaves and also in the presence 
or absence of a stalk to the strobilus. As a matter of fact, while it is an easy matter to 
distinguish a typical specimen of alpinum from a typical specimen of complanatum, there 
has been considerable diversity of opinion between British botanists whether Z. compla- 
natum has ever been found in this country, and whether these plants are not really 
specimens of L. alpinum. Even those favourably inclined to the inclusion of Z. compla- 
natum among British plants recognise only one or two localities for it, Mr. Baker was 
kind enough to supply me with a dried specimen of L. complanatum from Germany, and 
I am also indebted to him for confirming the names of some other specimens of Lycopods 
which I received unnamed. Interest attaches to Z. Chamecyparissus because Sachs's 
historic figure is referred to that species. A herbarium specimen was obtained which 
was not suitable for detailed examination. 
In several respects the three forms are similar in their external characters. The main 
stems are distinctly dorsiventral, the leaves on the stem are few in number, but the leaf- 
oe well marked. First-order branches are produced only at considerable distances, 
2 aceti ji : Punt order are "Heras and tallaw upon one another quickly, with 
| assel of branches may be found arising on branches of the first or 
second order. 
` beg F a PSN à =- mg and L Chamecyparissus are practically 
sui Nu: P adr TER nies is e "ya sections of L. clavatum.. Probably the 
a te a X, which shows three zones, but the innermost zone 
> ae ns e a a N defined and does not assume the appearance 
| , | uced to one or two layers. A considerable 
AETHERE NC EE QR 2 SEENE ASN CN 
