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changes perpetually occurring in the condition of the earth’s surface, 
render large tracts of land incapable of sustaining any longer certain 
species which formerly hid the soil with their luxuriant foliage: we 
know that thousands of such species did exist, and do not exist; but 
that their history is preserved for ever in Geology, that glorious book 
whose pages are traced by Nature’s own hand upon tablets of ada- 
mant. The hypothesis that Nature is compensating her losses by new 
creations, requires the recommendation of proof. All our Floras tell 
a different tale. The links which once connected Equisetum to Chara 
or to Isoétes have since perished, and no others have been supplied ; 
so that those genera stand alone and insulated, while all around them 
has disappeared: just as solitary specks of uninhabitable land, peep- 
ing up in the boundless ocean, are said to testify of a continent 
submerged. Whoever reads these circumstances aright, will fully 
appreciate the difficulty under which those are labouring who en- 
deavour to build a system of such scanty materials. Deeply im- 
pressed with this difficulty, I have thought it better to preserve 
intact the arrangement which I originally proposed, than to attempt a 
new one; at the same time giving an outline of a plan which I believe 
more in accordance with Nature. 
“It may here be observed, that in the various systems proposed or 
indicated by general botanists, as Ray, Linneus, Antoine de Jussieu, 
Agardh, Perleb, Dumortier, Bartling, Hess, Schultz, Fries, Endlicher, 
Brongniart, Meisner, Adrian de Jussieu, and Lindley, there is a most 
evident tendency to depreciate, or rather to under-estimate, the flower- 
less plants. Whether they were called simply “ flowerless,” as by 
Ray; “ Cryptogams,” as by Linneus; ‘‘ Acotyledons,” as by the 
elder Jussieu and Decandolle; little has been done beyond the mere 
change of name. All these authors appear either to ignore or to dis- 
regard the extreme fallacy of divisions founded on a mere positive and 
negative. Nothing is more simple than the division of all plants into 
those which have flowers, and those which have not: but something 
more is required, for positive and negative characters might be made 
the basis of the most unnatural divisions. 
“ Cuvier, in his ‘ Animal Kingdom,’ a work unapproached, perhaps 
unapproachable, in its masterly and philosophical grouping, has 
shown the plans on which all animals are constructed. He ignores 
the positive and negative of vertebrate and non-vertebrate, and 
employs positive characters only in defining his divisions ; these are 
Vertebrates, Mollusks, Articulates, and Radiates: and a little reflec- 
tion will convince any botanist that there are four great divisions of 
So ep ASSP 
