ANATOMY OF THE ROOTS OF PALMS, 465 
(22) Laranta Lopprersi, Mart. 
The limiting-layer is exfoliated and a zone of elongated more or less lignified elements 
occupies the periphery ; a parenchymatous cortex follows, in which occur comparatively 
small and irregular air-spaces and a few lignified and pitted elements. The innermost 
cortical zone consists of much more regularly arranged cells, without air-spaces, but 
with a considerable proportion of fibrous elements with thick lignified walls scattered 
irregularly and not grouped into bundles. 
The endodermic cells are thin-walled, non-cuticularized, and non-lignified. 
The pericycle is one cell in thickness opposite the xylem- and phloem-groups, two cells 
in thickness between these groups. 
The xylem and phloem are embedded in non-lignified prosenchyma, the inner portion 
of this zone alone being lignified, the process commencing internally and proceeding 
centrifugally. 
The large vessels of the interior are arranged roughly in one ring, but deep bays of 
prosenchyma projecting into the pith also enclose vessels occasionally. Small-celled 
groups occur amongst the large internal xylem-vessels. These appear to be of the 
nature of phloem, but differentiation has not gone far enough to state with certainty. 
A parenchymatous pith occupies the centre of the root in which runs a single 
prosenchymatous strand, the outer elements of which are lignified, lignification 
proceeding centripetally. 
This strand encloses a single large vessel. 
(23) LATANIA COMMERSONI, Mart. 
The outer cortex forms a narrow zone. The inner parenchymatous cortex possesses 
small irregular air-spaces and bundles of well-developed strongly lignified fibres with 
stegmata. The endodermis is thin-walled and non-lignified. The perieycle is one- 
layered. 
'l'here is à broad zone of sclerenchyma enclosing centrally a very irregular pith. "The 
xylem and phloem lie in the sclerenchymatous zone. : ; 
The protoxylem-groups, as usual, are arranged peripherally, while the large internal 
vessels are scattered throughout the sclerenchyma, without relation to the protoxylem- 
groups. The phloem-groups alternating with the protoxylem-groups are practically 
undeveloped, but scattered patches of phloem lie amongst the large internal vessels of 
the xylem, being distributed centrally nearly as far as are these vessels. 
III. LEPIDOCARYIN.E. 
(24) RAPHIA Rurrra, Mart. 
The limiting-layer cells are somewhat elongated ; these together with the three or 
four underlying layers, which are composed of cells of similar form, are slightly 
cuticularized. ‘They are succeeded by a zone of lignified elongated cells, more or less 
square-ended. The parenchymatous inner cortex has large and irregular air-spaces, often 
