224 South and Compton . 
plane for about 4 cms. and bifurcate; the two halves, then turning 
to right and left, girdle the stem horizontally. Sections of the 
cortical zone shew a great number of these girdle-bundles, two 
of which enter each leaf-base, from right and left; these quickly 
branch in the petiole to form the complicated system described 
by Mettenius 1 . 
At two points in the trunk, respectively 22 cms. and 48 cms. 
above the ground, a ring of bundles arises internally from the 
main cylinder, and pursues an oblique curving course in the 
medulla, with the result that a dome-like system of vascular tissue 
is produced (Figs. 35, 36, 38, vas, cyl. II.) As the dome con¬ 
tracts towards the top, the individual bundles anastomose, and 
eventually form a few broad strands arranged in a narrow cylinder. 
In this condition the vascular tissue bends over to one side; 
passing through a gap in the cauline cylinder, this peduncular 
cylinder—for such is its nature—bends slightly downwards and 
enters the cortex (Fig. 36, ped. cyl.) The base of the peduncle 
Fig. 36. Dissection of a hemi-cylindrical piece of the trunk, the vertical 
section passing through the point of egress of the peduncular cylinder. 
l.t. II., leaf-trace from the inner dome; ped., peduncle; ped. cyl., 
peduncular cylinder; a., incurved lip of vas. cyl. I. at point of egress 
of ped. cyl. ; b., aborted bud. Other letters as in Fig. 35. 
remains in a somewhat crushed condition, projecting laterally 
from the stem and hidden by persistent leaf-bases. Close beneath 
the peduncle, but slightly to one side, a small aborted bud is 
1 Beitriige z. Anat. der Cycadeen; Abhandl. d. k. Sachs Ges. d, 
Wiss,, 1860. 
