rongniart has since inclined to regard it as
cycadeous; nor is the French botanist satisfied that some
specimens of supposed palm wood from the coal-mines of Radnitz
in Bohemia, described by Corda, really belong to palms. On the
other hand, Corda has proved Flabellaria borassifolia of
Sternberg to be an exogenous plant, and Brongniart contends
that it was allied to the Cycadeae. See Tableau des Genres de
Vagataux Fossiles. Paris, 1849.

[158] Prodrome d'une Hist. des Vagat. Foss. p. 179. See also a
late paper, Quart. Journ. of Geol. Soc. London, 1846, in which
coal-plants of Alabama, lat. 33 degrees N., collected by the
author, are identified by Mr. Bunbury with British fossil
species, showing the great southern extension of this flora.

[159] Konig, Journ. of Sci., vol. xv. p. 20. Mr. Konig informs
me that he no longer believes any of these fossils to be tree
ferns, as he at first stated, but that they agree generically
with plants in our English coal-beds. The Melville Island
specimens, now in the British Museum, are very obscure
impressions.

[160] Fossil Flora of Great Britain, by John Lindley and
William Hutton, Esqrs., No. IV.

[161] Fossil Flora of Great Britain, by John Lindley and
William Hutton, Esqrs. No. IV.

[162] Fossil Flora, No. X.

[163] This has been proved by Mr. Lindley's experiments, ibid.
No. XVII.

[164] I have treated of this subject in my Manual of Geology,
and still more fully in my Travels in N. America, vol. ii. p.
178. For a full account of the facts at present known, and the
theories entertained by the most eminent geologists and
botanists on this subject, see Mr. Horner's Anniversary Address
to the Geological Society of London, February, 1846. Consult
also Sir H. de la Beche, on the formation of rocks in South
Wales, Memoirs of Geol. Survey of Great Britain, 1846, p. 1 to
296.

[165] The theory proposed in this and the following chapters,
to account for former fluctuations of climate at successive
geological periods, agrees in every essential particular, and
has indeed been reprinted almost verbatim from that published
by me twenty years ago in the first edition of my Principles,
1830. It was referred to by Sir