On the Stem-Structure of Actinostemma 
biglandulosa. 
BY 
WILLIAM WALLACE, B.Sc. (St. And.). 
With Plate XXXIV. 
Introduction. 
T HE following are the main features of interest in the 
anatomy of this stem :— 
i. The vascular bundles are primarily collateral and 
remain so for a relatively long period. It is not until 
secondary thickening has made considerable progress within 
the bundles that these begin to acquire medullary phloem. 
2. At the base of the older stem are a number of accessory 
bundles. These have a longitudinal course in the cortex 
and proceed from a meristem which has its origin in the 
endodermis. 
The plant investigated was reared in one of the plant 
houses of the Royal Botanic Garden, Edinburgh. Belonging 
to the family Fevilleae-Gomphogyneae of the order Cucur- 
bitaceae (Engler and Prantl), it is a tendriliferous liane 
with an animal stem, which, in its upper parts, is slender, 
cylindrical, and five-angled. A technical description of this 
species is given in Hooker’s leones Plantarum for 1899. 
The primary structure, as seen in transverse sections of 
a young internode, shows the following arrangement of the 
vascular tissues (PI. XXXIV, Fig. 1). There are five outer 
[Annals of Botany, Vol. XIV. No. LVI. December, 1900.] 
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