480 DR. ERIC DRABBLE ON THE 
feature is the presence of two or three small vessels interior to the large internal 
elements. ‘The pith is large and parenchymatous, with small air-spaces and fibres like 
those of the cortex. 
(51) DICTYOSPERMA ALBUM, H. Wendl. et Drude. 
The limiting-layer is normal, and is succeeded by a zone of lignified elongated cells 
with dark mucilaginous contents. This again is succeeded by a zone of fibrous elements 
among which are scattered some parenchymatous cells ; more internally the parenchyma 
very greatly preponderates, and the fibres are here arranged in definite bundles, very 
abundantly developed. In this zone small irregular air-spaces occur. The endodermis 
is lignified. 
The pericycle is one- or two-layered. Inside this lies a zone of lignified thick-walled 
fibres in which are embedded the xylem and phloem. The vascular elements occupy 
only the periphery of the central cylinder. V’s are occasionally found in the xylem, but 
not in the phloem. A few medullary strands of fibrous tissue, containing one large 
vessel, sometimes accompanied by one or two smaller ones, generally occur. In the pith 
some individual fibres are present, but no fibrous bundles like those of the cortex. 
Proximally a gap in the ‘cylinder is present and the edges are rounded off and 
inturned; the endodermis follows these and is finally lost in the ground-tissue, being 
thus incomplete across the gap. 
The latest gap to close up is on the adaxial side of the cylinder. In this region there 
is greater development of the medullary fibrous groups with central vessels, as well as 
greater central extension of the large vessels of the cylinder. 
Still more proximally the cylinder is more strongly lobed. 
(52) PINANGA sp. 
The limiting and tegumentary layers are developed as usual. In the external layers 
of the inner parenchymatous cortex are individual fibres, resembling those generally 
occurring in very definite strands. More internally fibrous strands of the type found in 
Kentia occur. The endodermis is lignified and the pericycle one-layered. A comparatively 
narrow, but very definite fibrous zone contains the xylem and phloem. V-formation is 
not often found, but is very well shown when it does occur. In the pith occur strands 
of fibres like those of the cortex; air-spaces and mucilage elements with dark contents 
are also present. 
(53) PiNANGA Kva, Blume. 
The external layers agree generally with those in the last species. The air-spaces of 
the inner cortex are, however, much larger and more definite. The endodermis and 
pericycle are similar, as is also the fibrous zone. Only one ring of internal vessels occurs, 
and they are comparatively small and peripherally situated, and the protoxylem-groups 
are widely separated. V-formation is unusual, but is found occasionally. Two groups 
of fibrous tissue were found in the pith, and a third not quite free from the fibrous zone, 
each with a single internal vessel. 
In the pith are mucilage-spaces and bundles of fibres. 
