462 DR. ERIC DRABBLE ON THE 
V-formation. In the centre is a parenchymatous pith, through which runs a single 
sclerenchymatous strand, enclosing a central vessel. This strand was followed for more 
than 12 ems. as a freely running strand without exhibiting any tendency to fusion with 
the sclerenchymatous zone. The central element in this strand was clearly shown to be 
a normal vessel, similar to the larger vessels occurring in the sclerenchymatous zone. 
(15) LrvrsrONA OLIVJEFORMIS, Mart. 
The limiting-layer is almost entirely exfoliated and is sueceeded by a few layers of 
square-ended, oblong cells, more or less lignified. These pass gradually into fibrous 
elements internally, which become lignified centrifugally. Then follows the parenchy- 
matous cortex with comparatively small and very irregular air-spaces and some lignified 
elongated individual elements. The endodermis is like that in Livistona rotundifolia. 
The pericycle is two cells in thickness and encloses the sclerenchymatous zone in which 
the xylem and phloem lie. Irregular V's are formed, and the large vessels extend some 
distance internally. ‘The central pith is not very clearly delimited from the sclerenchy- 
matous zone ; it consists of parenchyma with many irregular air-spaces. 
(16) Livisrona CHINENSIS, Hort. 
The limiting-layer is entirely exfoliated. The periphery is occupied by a zone four 
elements in thickness, much lignified and thickened, and is followed by thin-walled 
prosenchymatous cells which more internally exhibit lignification. The inner parenchy- 
matous cortex has small air-spaces and some square-ended, pitted, lignified cells. The 
endodermis and pericycle resemble those of the other species of ZLivistona examined. 
The protoxylem-groups and the phloem occupy the periphery of the central cylinder 
and are embedded in a sclerenchymatous zone. The larger vessels extend some distance 
internally. In roots of small diameter the medulla is entirely parenchymatous, but in 
larger roots several sclerenchymatous strands in which are embedded one or two vessels 
traverse the medulla. Generally these strands are quite free from the sclerenchy uum 
zone, but occasionally one is seen in lateral continuity with it. 
The central cylinder shows in the larger roots a slight lateral invagination, into whieh 
the endodermis extends. 
This is the only irregularity in these roots. 
(17) SABAL GLAUCESCENS, Lodd. 
The limiting-layer is composed of isodiametric, thin-walled, lignified cells. Under 
this layer are several layers of lignified fibrous cells, a single layer in the middle being 
non-lignified. This zone passes gradually into a large-celled parenchymatous cortex with 
large irregular air-spaces. There are no fibrous elements and comparatively little thin- 
walled lignified parenchyma. In some cases the remains of ‘the elements whose 
disorganization has given rise to the air-spaces are very well shown. The innermost 
layers of the cortex are more compact and without air-spaces. The endodermie cells 
are about six times as long as broad and of the usual lignified type. The pericycle is 
leefs. 
