24 MR. C. E. JONES ON THE MORPHOLOGY 
rule. The stem (Pl. 3. fig. 4 and Pl. 4. fig. 24) shows very distinctly the characters 
mentioned above; in the centre one or two groups of sieve-tubes with the surrounding 
parenchyma are isolated as islands, and a similar arrangement of phloem is quite as 
distinet towards the outside. It will be noticed, too (fig. 24), that there is a break in the 
connection between the protoxylem and the central tissues of metaxylem at five points, 
and this break occurs in the metaxylem and not where the protoxylem passes into 
metaxylem. At the position ». (PJ. 3. fig. 4), a root is coming off, and it will be seen 
that the vaseular tissue of the root joins on to two protoxylems and one phloem of the 
stem. In the case of ali these epiphytie forms roots may be expected at the base 
of the stem; during the present investigation they were found only in this species, 
but that is accounted for by the fact that the material obtained of the other plants of 
this group did not come from the base. A figure is given in Engler and Prantl’s 
‘ Pilanzenfamilien’ (i. Teil, 4 Abt. fig. 365, p. 579), in which a root is shown traversing 
the cortex in the stem of L. Phlegmaria. 
LvcoPopruw DALHOUSIEANUM, Spring. 
On the oldest part of the stem of Lycopodium Dalhousieanum obtainable, which 
probably represented a branch of the first order, there were seven leaf-bases, which 
corresponded with an alternating arrangement of three or four leaves, but on a smailer 
branch there were regularly alternating whorls of three leaves. The vascular cylinder 
(PL. 3. fig. 5) is not so definite as in Z. squarrosum, but in the larger branches phloem- 
islands are quite distinguishable. A peculiar configuration is one exactly similar to that 
figured for L. Phlegmaria by Pritzel in the * Pflanzenfamilien ' (fig. 365 A, p. 579), in 
which there are two parallel strands of metaxylem separated by a phloem-band having 
the sieve-tubes in one line; but outside this the xylem-portions are feebly developed and 
isolated, and, as the structure of the branch was followed up, cross-connecting portions of 
the xylem were found, and a very detinite phloem-island was formed in the centre in 
which the sieve-tubes were characteristically grouped. The leaf-bases showed no well- 
defined mesophyll-cells, and intercellular spaces were not very apparent—both of which 
facts may be correlated with the well-marked development of the leaves. 
LYCOPODIUM PHLEGMARIA, Linn. ; LYCOPODIUM NUMMULARIFOLIUM, Blume. 
These epiphytic species—the former with a wide distribution through the tropics of the 
Old World, the latter confined to the Malay Region and the islands to the east—both 
correspond with the squarrosum type. 
The material available in the case of each of these species consisted only of branches, 
and in consequence, as may be scen from the diagram, the sections of L. Phlegmaria do 
not show the phloem-islands clearly delimited throughout, although the isolated portions 
of the xylem are well marked; but the section of L. nummularifolium represented in the — 
diagram (Pl. 4. fig. 25) is distinctly radial and the phloem-islands with the grouped 4 
sieve-tubes are quite definite. The radial construction of L. nummularifolium is — 
especially noticeable as contrasted with the dorsiventral arrangement of the leaves. 5 
