226 
South and Compton. 
narrows, bends over, and passes out horizontally to the remains of 
the peduncle. The leaf-bases have for the most part been removed, 
and much of the parenchymatous tissue of cortex and pith has 
been dissected away, in order to expose the vascular skeleton. 
i 
V&S. cull. -t 
J I 
iras.cyl.n: -• 
i 
i 
i 
l 
i 
l 
Fig. 38. Diagram of the vascular arrangement after the lateral bud has 
become terminal in position. Letters as in Fig. 2. 
The minute anatomy of the vascular tissues is of the well- 
known type. The xylem of the axial cylinder consists of a very 
large number of radial rows of tracheids, mixed with uni- or bi- 
seriate rows of parenchyma, these continuing outwards through 
the phloem. The protoxylem and protophloem are in a crushed 
condition. The cambium is broad, and the processes of growth 
and lignification appear to be slow. Xylem and phloem are present 
in about equal bulk. Anomalous cylinders, such as are found in 
Cycns, Enceplialartos, Macrozamia, &c., are absent; and bundles 
with inverse orientation appear not to be developed; there is 
no trace of the medullary vascular network so conspicuous in 
Macrozamia and Cycas\ The stem structure thus approximates 
more closely to the type of Stangeria paradoxa 3 . 
II.—Peduncular Cylinder. 
Where the main vascular system narrows into the peduncular 
cylinder (Fig. II., ped. cyl.) the bundles unite laterally: the main 
medullary rays become reduced in number, but the radial uni- 
seriate rows of parenchymatous cells persist. At the base of the 
peduncle, below the insertion of the sporophylls, the main vascular 
tissue is arranged in a regular ring of about five strands separated 
by medullary rays of about four cells broad. No trace of centri- 
1 Worsdell: Ann. Bot. X., p. 601, 1896. 
2 Solms-Laubach : Bot. Zeit, 1890, Nos. 12-15. 
