104 
PROFESSOR W. C. WILLIAMSON ON THE ORGANISATION 
Plate. 
Figure. 
Page at which 
reference is 
made to the 
figure. 
12 
G 
Slightly oblique, long, tangential section (passing out 
of the tissue at its upper part) of the outer cortex 
of a stem of Lyginodendron Oldliamium : f, paren¬ 
chymatous areas, corresponding to those f,foi figs. 
1 and 3 ; g, g, laminae of fibrous prosenchyma, 
corresponding to g, g of figs. 1 and 3 ; A, li, h ", 
numerous variously intersected peripheral emer¬ 
gences. X 20. Cabinet number, 1144 
90-91 
13 
7 
Transverse section of a young petiole, Rachiopteris 
aspera, fringed with a number of peripheral emer¬ 
gences, A, h, similar to those of fig. 6. X 20. 
(yabinet number, 1191. 
91 
12 
8 
Longitudinal section of a small petiole, like fig. 7, 
with its peripheral emergences. A, li . 
91 
13 
9 
Portion of the outer cortex of a transverse section of a 
Lyginodendron Oldliamium, showing, at A, li, an 
emergence resembling that at fig. 3, li, and demon¬ 
strating the origin of its outer prosenchymatous 
coat as an extension of the sclerous prosenchymatous 
l^ands, g, g, wdiilst its inner parenchyma. A', is 
derived from one of the parenchymatous alternating 
areas, f, of the outer cortex. X 40. Cabinet 
number, 1141. 
91 
13 
10 
Transverse section of a young branch of Lyginodendron 
Oldharnium, prior to its emergence from the cortex 
of the parent stem : a, central mass of closely aggre¬ 
gated tracheae; h, investing zone of radiating, exo¬ 
genously developed tracheae, otherwise similar to the 
centi’al ones, a. X 30. Cabinet number, 1885 A . 
1 
j 
1 
92-95 
13 
11 
A similar section to, but of a somewdiat older branch 
than, that represented in fig. 10. A vacant area at a, 
the result of the dissociation of the central mass of 
tracheae, fig. 10, a, and their separation into the 
detached groups, a, a. The exogenous zone, as 
before, at 6, 6. X 30. Cabinet number, 1885 H . 
92-95 
