INTERNAL STRUCTURE OF TRUNKS. 4.07 
I must refer to the memoir, in which these 
Sections are described, for specific details as to 
varied proportions and numerical distribu- 
tion of these concentric circles of laminated u ood 
^od cellular tissue, in the trunks of living and 
iossil species of Cycadete.* 
A strict correspondence is also exhibited in 
* Plates 60, Fig. 1, and 61, Fig. 1, represent very perfect 
specimens of fossil Cycadites from Portland, now in the Oxford 
Museum ; both having the important character of Buds pro- 
’^■'uding from the Axillae of the leaf stalks. 
The section given in PI. .59, Fig. 2, of the trunk of a recent 
'tmia horrida, from the Cape of Good Hope, displays a structure 
^‘railar to that in the section of the fossil Cycadites megalophyllus 
ton) the Isle of Portland ; (PI. 60, Fig. 2) each presents a single 
Circle of radiating larain® of woody fibre, B, placed between a 
Central mass of cellular tissue, A, and an exterior circle of the 
Same tissue, C. Around the trunk, thus constituted of three 
P^rts, is placed a case or false bark, D, composed of the persis- 
ent bases of fallen leaves, and of abortive scales. The continu- 
of the same structure is seen at the summit of the stem, PI, 
Fig. 1, A. B. C. D. 
The Cycadites microphyllus, PI. 61, Fig. ], affords a similar 
^PProach to the internal structure of the stem in the recent 
^ycas. The summit of this fossil exhibits a central mass of cel- 
tissue (A), surrounded by two circles of radiating woody 
^^ates, B. b., between these laminated circles, is a narrow circle 
cellular tissue, whilst a broader circle of similar cellular tissue 
leaf ** P^^ced between the exterior laminated circle, (b) and the 
. Scales (D). This alternation of radiating circles of wood 
circles of cellular tissue, is similar to the two laminated 
® ycung stem of Cycas revoluta, (PI. 
ca 'i^'.° This section was communicated to mo by Mr. Brown 
y ni 1828, to confirm the analogy which had been suggested 
the external surface, between these fossils, and the recent 
ycade® ; and jg figured in Geol. Trans. N. S. vol. ii. PI. 46. 
G. 
K K 
