FOSSIL ANGIOSPERMS. 199 
It would be impossible, within the limits necessarily 
assigned to these volumes, to offer even a general view of 
the fossil remains of this grand class of vegetables; our 
remarks must be limited to a few interesting examples and 
localities. 
When stems of dicotyledonous trees only are found, but 
- little certainty can be obtained as to the family to which 
_ they belonged ; the foliage of many well-known genera offer 
more positive characters; the flowers are rarely in a state 
of preservation to afford any valuable data ; but the fruits, 
or seed-vessels, are frequently well preserved, and these may 
_ enable the botanist to arrive at precise determinations as to 
generic, and, perhaps, specific relations. 
The tertiary marls of Aix, in Provence, which abound 
in insects, crustaceans, and lacustrine shells, contain many 
kinds of dicotyledonous leaves, associated with those of palms. 
(Wond. p. 260.) 
The Lignite, or Brown-coal deposits, are almost entirely 
composed of dicotyledonous trees, belonging to many genera, 
which are inhabitants of Europe ; namely, the Poplar, Willow, 
Km, Chestnut, Walnut,Sycamore, Maple, Linden, Buckthorn, 
Vine, &e. (bd. vol. i. pp. 508—514.) 
The beds of brown coal, on the banks of the Rhine, are 
literally carbonized submerged forests, which in some re- 
mote period were drifted from the interior of the Continent 
into a vast lake or gulf; for the trees bear evident marks of 
transport, and are destitute of roots and branches. These 
masses resemble the rafts of forest-trees, which are daily 
floated down the Mississippi into the Atlantic, where they 
become engulfed in the profound depths of the ocean, and 
probably will be converted into coal or lignite; and in 
future ages, may be elevated above the waters, become 
dry land, and present to the then existing communities 
of mankind an inexhaustible supply of mineral fuel, com- 
posed of species and genera of plants, which possibly may 
