ANATOMY OF THE ROOTS OF PALMS. 475 
(44) EUTERPE sp. 
. The limiting-layer is slightly lignified. It is succeeded by a narrow zone of small 
elongated lignified elements. Through the parenchymatous inner cortex run lignified 
fibres with transverse walls, and also other lignified elements arranged in strands, whose 
fibrous nature is not nearly so evident. The air-spaces are large and irregular. The 
innermost cortical zone is much denser than the rest and is without air-spaces. The 
endodermis is lignified, and the pericycle one or two cells in thickness. The fibrous zone 
is of comparatively small width, and contains the xylem- and phloem-groups. Xylem V's 
are of frequent occurrence. There is only one ring of large internal vessels, and these 
are very peripherally placed. The pith is large and parenchymatous and contains 
regular air-spaces. 
(45) KENTIA sp. 
The peripheral layer is composed of large isodiametrie thin-walled lignified cells. 
These are followed by elongated lignified small elements, the outer of which are provided 
with dark contents. These pass internally into more densely lignified fibrous elements 
and these again are followed by the parenchymatous cortex with its large irregular air- 
spaces and bundles of fibres. These fibrous bundles, though fairly definite, are not by 
any means so well formed as those in Raphia Hookeri for example, and in other roots 
provided with stegmata. The fibres themselves are much broader, relatively thinner- 
walled, and with more considerable lumina, closely resembling those found in Areca 
concinna. The endodermis is much lignified and thickened on all but the outer 
tangential walls. The pericycle is generally two elements in thickness, but opposite to 
the protoxylem-groups it may be reduced to one. The xylem and phloem are embedded 
in a lignified zone of fibrous elements. Xylem V's are of frequent occurrence. There 
is only one irregular ring of large internal vessels. Centrally there is a parenchymatous 
pith in which lie some pitted fibres. 
In large roots, passing from distal sections to proximal ones, the following stages are 
observed :— 
(a) Outer cortex parenchymatous, with no air-spaces, but with sparsely scattered 
fibrous elements. Inner cortex of larger parenchymatous cells, among which run 
fibrous bundles and large air-spaces. The central cylinder presents a slightly lobed 
outline, the endodermis dipping into the lobes, but being quite continuous. The 
cylinder is incomplete on one side, and here the endodermis follows the incurved edges 
of the fibrous zone, and is lost internally in the parenchymatous ground-tissta: These 
free edges of the fibrous zone are very much inrolled, carrying m with them at least two 
phloem-groups. The gap between them is broad, and through it the ground-tissues of 
cortex and medulla are continuous. In both are embedded exaetly similar fibrous 
bundles, except that those of the pith tend to be slightly less strongly lignified. 
(b) In a section taken more proximally the cylinder is still. more lobed, and several 
gaps, bounded by the inrolled edges of the fibrous zone, are present. Into these gaps 
the endodermis dips and is lost. Some of the arcs of fibrous tissue are so greatly 
SECOND SERIES.— BOTANY, VOL. VI. 3 Y 
