90 Geological Society of London. 
Similar remarks hold in regard to the observations made by M. 
Virlet in the Dictionnaire d’Hist. Naturelle, where in his late article 
“De l’Origine des Combustibles Minéraux,” he speaks of certain 
carboniferous deposits of Ireland, (those alluded to by Mr. Weaver 
before mentioned,) as well as others examined by M. Voltz in the 
Black Forest, also the culm beds of Britanny, and those of the de- 
partment of La Sarthe, as all belonging in age to the newest transi- 
tion formations, “ terrains de transition les plus récens.” 
r. De Ja Beche alludes to another discovery of coal plants im- 
plying as great an anomaly as that which he had imagined to occur 
in Devonshire, and by which he was himself once led into error du- 
ring an Alpine excursion, about eighteen years since, when he met 
with coal plants in the schists of the Col de Balme, in Switzerland. 
He then inferred that the beds belonged to the true coal measures, 
but M. Elie de Beaumont afterwards proved them to be lias; that is 
to say, he identified them with other rocks not far distant in the Alps, 
which were shown to be lias by containing Belemnites and other fos- 
sils. Mr. De la Beche was at first sceptical on the point, but after 
revisiting the Alps, he came round to the same opinion. Having 
therefore been in one instance misled by relying on the fossil vege- 
tables of the coal as affording a good chronological test, he naturally » 
attached but small value to the same testimony as a criterion of the 
age of another set of rocks in Devonshire. Now you will easily un- 
derstand that a geologist, who is once persuaded that the same plants 
flourished in European latitudes from the period of the true coal to 
that of the lias, will be ready to concede without difficulty the prob- 
able existence of the same plants at an era long antecedent to the 
coal. We know that between the deposition of the coal and the lias 
there were successive revolutions in the races of animals which in- 
habited the waters; the zoophytes, mollusca, fish, and, as far as we 
know them, the reptiles having been changed again and again; $0 
that the fossils of the mountain limestone differ from those of the 
magnesian limestone or zechstein, these again from the organic re- 
mains of the muschelkalk, and these last from those of the lias. If 
we are to believe that the same plants survived on the land, while 
such fluctuations in animal life occurred in the waters, why should 
we not imagine the longevity of the same species to have been st) 
greater, so that they began to exist even before the deposition of the 
old red sandstone? But let me remind you that botanists have been 
Jed to very different conclusions respecting the laws governing the 
