84 
A NOTE ON THE WOOD OF GNETUM GNEMON 
In the region of the phloem the rays are unlignified, and small fusiform 
rays 1 or 2 cells in width and several high, like those described for 
G. africmum 1 , are present in the phloem. 
Phloem. 
The sieve tubes are arranged in radial rows and have large compound 
sieve plates on their very oblique end walls. On the radial walls sieve areas 
are found fairly widely apart. In this material very little callus has been 
formed. 
The albuminous cells are arranged in radial rows between the sieve 
tubes, and contain starch grains. Their cross-walls are for the most part 
transverse, sometimes oblique. 
The outer zone of the phloem in old stems is not functional, some of the 
cells becoming very much sclerified. These occur in groups surrounded by 
collapsed cells, and contain large crystals. The nature of these crystals has 
not been determined, but is under investigation. They are probably identical 
with those crystals described as crystal sand 1 . 
Mr Burkill, in his letter, quotes the following extract from Marsden’s 
History of Sumatra : “ The bagu tree ( Gnetum gnemon) abounds on the 
southern coast of the island, where its bark is beaten, like hemp, and the 
twine manufactured from it is employed in the construction of large fishing 
nets.” This can refer only to the sclerified cells in the phloem and cortex. 
Epidermis, Cortex, etc. 
The epidermal cells are papillate and possess a thick cuticle. Fibres 
are present in the cortex of young stems, and amongst the parenchyma inside 
arid outside the sclerenchymatous zone in the cortex of old stems. They are 
very long and have pointed ends, and their thickening is white and shiny. 
In young stems there is an irregular ring of lignified parenchyma cells 
with simple pits a few cells beyond the phloem. In old stems these cells 
become sclerified and form a broad zone in the cortex. Outside this zone 
occasional masses of sclerified cells are found scattered in the parenchyma. 
There is no indication of groups of fibres surrounded by cork as described for 
G. africanuvi 2 . 
Latex tubes are present in the cortex of both node and internode and 
lignified stellate cells in the cortex of the node. 
The origin of the cork (fig. 7) differs from that of G. africanum 2 in being 
subepidermal, not epidermal. The cork at first appears as small roundish 
dots irregularly distributed on the stem. 
In conclusion I desire to express my thanks to Dr Pearson for handing 
over the material to me for investigation, and for much helpful advice with 
regard to the work. 
1 Duthie, 1912. 
2 Duthie, 1912. 
