13 
representatives of all those which are either constantly 
present in the coal measures, or as universally absent. The 
vessel was placed in the open air, left uncovered and left 
untouched, with the exception of filling up the water as it 
evaporated, till the 22nd of April, 1835, that is, rather 
more than two years. At the end of that time, what 
remained was examined, when it was found that of the 177 
only 56 remained recognisable; 121 were entirely decom- 
posed, and those which resisted were precisely such plants 
as we now find fossil." From these facts the Professor 
deduced the following important conclusions : — 
" 1st. That Dicotyledonous plants in general are not 
able to remain two years in water without being totally 
decomposed ; and that the principal part of those which do 
possess the power are Coniferse and Cycadese. 
" 2nd. That Monocotyledons are more capable of resisting 
the action of water, in particular Palms and Scitamineous 
plants, but that grasses and sedges perish ; so that we have 
no right to say that the earth was not originally clothed 
with grasses and other plants of a similar nature, because 
we no longer find their remains." 
Brongniart, however, (no mean authority on this subject,) 
advocates the contrary opinion. " The living vegetable 
kingdom," he observes, " consists of five great divisions, the 
Cellular Cryptogams or Amphigens ; the Vascular Cryp- 
togams or Acrogens; the Dicotyledonous Phanerogams; 
Gymnosperms and Angiosperms; and the Monocotyledonous 
Phanerogams. Of these five divisions, the three first evidently 
existed at the Carboniferous epoch ; whereas the two last 
seem to have been entirely wanting ; there is nothing, at 
least, which establishes, with certainty, their existence; and 
everything, on the contrary, tends to render it doubtful." 
Estimating the present vegetation of the globe in round 
numbers at 80,000 species, the Fossil Flora amounts to 
about of the living Flora. 
