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Analyses of Books. 
gin like the bases of the leaves in our fossil specimens. The cavity itself is occu- 
pied by a cluster of fronds producing the fruit or drupse ; and it is a striking coinci- 
dence, that Sir J. Smith, in describing this cavity, makes use of the same compari- 
son (hollow like a bird’s nest) which has been applied by the quarry men at Portland 
to the fossils I am now associating with the recent Cycadese. In the central cavity 
of this fossil, there are no remains of frond or fruit, but a convex mass of cellular 
tissue, which probably formed the support of the proliferous fronds. Where the 
trunk is broken belowathe summit, we find the same central mass of cellular tissue 
as in the transverse section of the stems of recent Zamia: and Cycades." 
“ Near the circumference of both specimens there is a laminated circle as in the 
trunk of a recent Zamia, but differing in that it is much broader and placed nearer 
the circumference of the stem : the large and visible plates of the circle, when mag- 
nified with a lens, appear made up of smaller plates almost invisible to the naked 
eye, more numerous and closer to each other than in the laminated circles of a re- 
cent Zamia.” 
“ Between this radiating circle and the other case of leaf stalks, is a narrow band 
or ring of minutely cellular substance, analogous to the. similar but much broader 
band of cellular tissue that divides the radiating circles from the bases of the leaves 
on the recent Cycadem.” 
“ In the second and smaller species ( Cycadeoidea micrrophyUa ) the bases of the 
leaves are also lozenge shaped and about an inch in length, but small and numerous, 
much like those of the Xanthorrhaea or gum plant of New South Wales. The trunk 
is longer in proportion to its width, whilst its transverse section exhibits atthe centre 
the same indistinctly cellular appearance as the species last described ; but near the 
circumference instead of one it has two laminated circles, and interior to each of 
these a narrow hand devoid of lamime, analogous to the two bands of cellular sub- 
stance that are placed in similar relation to the two laminated circles in a recent 
Cycas.” 
“ These two circles, like the one circle of Cycadeoidea vnegalophylla , approach the 
circumference, whilst those in Zamia and Cycas are placed nearer the centre of the 
stem." 
“There is also a further analogy between this fossil species, and the recent Cycas, 
viz. that, in each case the outermost of the plated circles is the most narrow of the 
two, and the cellular band between, is in both cases also narrow." 
“ The engraving of Cycas revoluta, copied from tbe Hortm Malabaricus, exhibits 
many plated circles divided from one another by narrow cellular bands, and these 
also are placed nearer to the centre than to the circumference of the stem.” 
It appears from these and other details that the fossil plants approach something 
nearer to the structure of dicotyledonous woods than the Cycadeae ; and that they 
form a link between these latter and the conifera, from which they are otherwise so 
widely separated, though resembling them perfectly in the character of their organs 
of fructification. 
From the particulars of various, hitherto considered anomalous, fossils collated 
by Dr.Buckland, he draws the conclusion, that one or both of the cognate families 
of the Cycadem and Cycadeoidea; belong to the beds of the Oolite series. 
“ M- Adolphe Brogniart has pointed out the inferences with respect to climate 
that may be drawn from the varying character of vegetable life in the three grand 
epochs of geological formation : viz. the great carboniferous period : the period of 
the secondary strata from lias to chalk inclusive ; and tbe period of the tertiary 
strata above the chalk.” 
“ The plants before us render it probable that the climate of these regions, at the 
time when the Oolites were deposited, was of the same warm temperature with that 
■which produces a large proportion of the existing Cycadeae. 
M. Adolphe Brogniart is also of opmiou, that it exceeded the temperature of our 
modern tropics at a still more early period when it maintained the extraordinary 
vegetation of the great coal formation; and that it was less than tropical, though 
warmer than it is at present, in the period to which we owe our tertiary strata. To 
this theory I see much reason to incline, and confidently look forward to its future 
development in the examination of the Flora of the fossil world, which he is now 
so actively conducting.” 
