78 G wynne- Vaughan. — Observations on the 
Luerssen 1 in Kaulfussia cicutifolia and other Marattiaceae , 
and they have since been described in the Ophioglossaceae, 
and in a number of Cyatheaceae and Polypodiaceae 2 . 
The annular stele is limited on either side by a very distinct 
endodermis, consisting of vertically elongated square-ended 
cells, easily distinguished from the rest of the ground-tissue 
by reason of their very dense grey-coloured contents (Figs. 2 
and 3, e, e). Some of the cells of the endodermis differ in 
appearance from the rest, owing to the more coarsely granular 
nature of their contents, which are also impregnated with 
tannin. No undulations were observed on the radial longi- 
tudinal walls, but they are more or less cutinized, especially 
at the angles. The pericycle forms a continuous zone within 
the endodermis on either side of the solenostele ; on the 
outer side, it consists of three to four layers of slightly 
elongated comparatively wide-lumened cells with finely pitted 
walls, the terminal walls being transverse or slightly oblique ; 
on the inner side of the solenostele it is less developed, two or 
three layers only being present. In sections near the apex, 
the cells of the pericycle are seen to be superposed upon each 
other and upon those of the endodermis with considerable 
regularity, and, allowance being made for displacement due to 
growth and subsequent division, there is but little doubt that 
they all originated from the subdivision of a single cell-layer 
of the ground-tissue, and that therefore the pericycle is not 
a true but a false one (cf. Fig. 3). 
The phloem, again, forms a continuous zone on either side 
of the solenostele, and, like the pericycle, is somewhat greater 
in quantity on the outer side than on the inner (Figs. 2 and 3, 
ph and pk ). It consists of sieve-tubes and phloem-paren- 
chyma. The sieve-tubes have their pores aggregated into 
definite areas, the sieve-plates, which are present on both the 
longitudinal and transverse walls ; further, the sieve-plates, as 
in the Cyatheaceae, are so numerous and occupy so much 
space that the thicker portions of the wall separating them 
1 Uber den Bau nnd die Entwickel. der Gefasskrypt., Bot. Zeit. , 1873, p. 640. 
2 Cf. De Bary, Comp. Anat. (Engl, ed.), p. 118. 
