A NOTE ON THE WOOD OF GNETUM GNEMON 
85 
Summary. 
The internodes examined showed from 27 to 29 vascular bundles in the 
ring with no centripetal wood or transfusion tracheids. Secondary thickening 
is normal and annual rings are absent. 
The pith is parenchymatous with a lignified zone in the region of the 
vascular bundles. The cells contain starch, and calcium oxalate in addition 
in the node. Latex tubes and stellate cells are present, and the central cells 
of the internodal pith become disorganised. 
The primary xylem shows spiral elements, some with a few annular 
thickenings, scalariform elements, arid elements showing a combination of 
scalariform thickening and bordered pits. 
The tracheids show usually uniseriate pitting, the outline of the pit being 
circular, the mouth oblong, and the torus not well developed. Striations are 
present, but bars of Sanio, trabeculae, and resin plates appear to be absent. 
Occasionally a transverse septum was found in a tracheid. 
In the vessels the multiseriate bordered pits are irregularly arranged. 
One large perforation is oftenest found, but several occur, and fusions of the 
perforations are seen. Striations are present in a few vessels, but bars of 
Sanio and trabeculae are not. 
The ray cells are lignified and simply pitted and contain starch and 
calcium oxalate crystals. 
Uniseriate and multiseriate rays are present, the latter being formed by 
radial division of the uniseriate rays and by fusion of smaller rays. 
Xylem parenchyma is abundant, but not equal in amount to the tracheids. 
The cells are lignified, uninucleate, and contain starch. Septa are numerous 
and mostly cellulose. These cells have probably been developed from tracheids. 
The phloem is composed of radial rows of sieve tubes and of albuminous 
cells, the former having compound sieve plates on their oblique end walls and 
sieve areas on their radial walls. Part of the phloem which is not functional 
becomes sclerified. 
The epidermal cells are papillate and possess a thick cuticle. 
Latex tubes and fibres are found in the cortex with the addition of 
lignified stellate cells in the node. 
Also there is a zone of sclerified cells outside the phloem legion. 
The cork originates in the subepidermal layer. 
Botanical Laboratory, 
South African College, 
May , 1916. 
