G tie turn africanum , with Notes on Gnetum scandens. 1105 
section. They branch freely, they are small and numerous, and associated 
with them are many transfusion tracheides which occur chiefly laterally on 
the phloem side of the bundle ( 7 >., Fig. 5, PI. LXXXVI). 1 
(b) The Course of the Bundles. The bundles run straight up the peduncle 
and internodes of the inflorescence without anastomosing. As they reach 
the base of the inflorescence they branch, and from two opposite points in 
the stele two single, usually concentric bundles arise. Each of these first 
bundles forms the median bundle of a bract supply and is speedily supple¬ 
mented by numerous other bundles, arising on each side of it from others of 
the bundles of the main axis. Many of the bundles, including the single 
median one, have a double origin from two of the bundles of the main axis, 
as shown in Text-fig. i. 2 
B 
ff//iliitiitW '"'iitinu, 1 
C 
/77m i 11 mTiTV' 
Text-fig. i, A, B, C, shows the origin of one of the concentric bract bundles from two 
bundles of the main axis. 
I had only two whole spikes among my material and in both cases 
there were no buds in the axils of the two basal bracts, so the vascular 
supply of axillary organs other than the flowers could not be investigated. 
The bundles supplying the bract cupul'es arise in a manner very similar 
to those supplying the bracts ; the median bundle is, however, not often 
clearly distinguishable, the bundles are more numerous and the general 
arrangement more irregular. The chief interest in the vascular system 
of the inflorescence of Gnetum lies in the origin of the two outer nodal 
rings of bundles and the method of formation of the bundle supply of the 
flowers. Worsdell 3 compares ‘ these transitory extra-fascicular rings of 
bundles with the more fixed extra-fascicular rings, of bundles in the 
vegetative axes of the Cycads ’; the former are almost all used up at each 
node by the bract and flower supplies, the latter are concerned with the leaf 
supplies and are therefore not persistent above the youngest leaf-trace. 
The course of the bundles through the node of the older inflorescences 
of Gnetum africanum is exceedingly complex, so the younger inflorescences 
of G. scandens will first be described. In G. scandens the simple ring of 
fibrovascular bundles has a long undisturbed course through the elongated 
internode, and the small size of the cushion at the node brings the insertion 
of the ovules closer in the axil of the cupule (see Fig. 1, PI, LXXXVI). 
1 As in Welwitschia ; Sykes, 1910 (1), p. 186. Cf. Worsdell, 1901, p. 767, on Ephedra 
distachya, where he found a few tracheides of centripetal xylem in the bract of the female 
inflorescence. 
2 A similar double origin of bundles is common throughout the inflorescence. Cf. Welwitschia , 
Sykes, 1910 (1), pp. 193, 204, &c, 
3 Worsdell, 1901, pp. 767-8. 
