Note. 
527 
that the greater part of the primary wood was centripetally developed, 
while a smaller portion was centrifugal. We propose to term such 
bundles viesoxylic or mesarch 1 . All statements as to the position of 
the protoxylem are based on longitudinal as well as on transverse 
sections. 
4. The Secondary Tissues. — A few young stems have been observed 
with little or no secondary thickening; in most specimens it has 
made considerable progress. A large amount of secondary wood and 
bast, both fascicular and interfascicular, was formed, by means of 
a normal cambial layer, which is often well preserved. 
The tracheides of the wood have numerous bordered pits on their 
radial surfaces. Similar elements occur in the primary wood also. 
The rows of tracheides are separated by numerous medullary rays. 
The phloem is often well preserved, so that primary and secondary 
phloem can be distinguished. 
The secondary tissues bear a general resemblance to those in the 
stems of Cycadeae. 
5. Pith and Pericycle. — Both these tissues contained nests of dark- 
coloured elements, probably of a sclerotic nature. They are also 
traversed by numerous rows of cells with carbonaceous contents, 
which may have been secretory sacs , but not intercellular canals. At 
the outer border of the pericycle a characteristic internal periderm 
was developed. 
6. The Cortex. — The parenchymatous portions of the outer cortex 
became much dilated in the older stems, in consequence of the 
secondary growth. 
7. On Small Stems of the Lyginodendron Type. — Certain very small 
stems have been described, differing in structure from the usual 
form. In some of these the primary xylem forms a continuous ring, 
instead of being divided into distinct bundles. We now suggest that 
these specimens may represent the basal , first-developed region, of 
normal stems. In Osmunda , which in many respects resembles 
Lyginodendron , it has been shown by M. Leclerc du Sablon, that the 
embryonic stem has the same peculiarity. 
8. Structural Anomalies. — Some of the specimens show remarkable 
individual anomalies, the most frequent and conspicuous of which 
1 One of the authors has recently found that this peculiarity sometimes extends 
to stem-structures in Cycadeae ; in the peduncles of both male and female flowers 
of Stangeria the bundles are often mesoxylic. 
O O 2 
