VEGETABLES IN THE TERTIARY FORMATIONS. 507 
ends ; extending backwards from the actual con- 
dition of our Planet through the manifold stages 
of change, which its ancient surface has under- 
gone.* : 
SECTION IV. 
VEGETABLES IN STRATA OF THE TERTIARY SERIES, j' 
It has been stated that the vegetation of the 
Tertiary period presents the general character 
of that of our existing Continents within the 
Temperate Zone. In Strata of this Series, 
Dicotyledonous Plants assume nearly the same 
proportions as at present, and are four or five 
times more numerous than the Monocotyledo- 
nous ; and the greater number of fossil Plants, 
although of extinct species, have much resem- 
blance to living Genera. 
This third great change in the vegetable king- 
dom is considered to supply another argument in 
favour of the opinion, that the temperature of 
the Atmosphere, has gone on continually dimi- 
nishing from the first commencement of life upon 
our globe. 
* Fruits of another genus of Pandanese, to which Mr. Ad. 
Brongniart has given the name of Pandanocarpum, {Prodrome, 
p. 138,) occur together with fruits of Cocoa nut, at an early 
period of the Tertiary formations, among the numerous fossil fruits 
that are found in the London-clay of the Isle of Sheppey. 
t See PI. 1, Figs, m to 72. 
