1831, and the recent
observations of Philippi in regard to the passage of species from
one formation to another. I refer to these authorities more
especially because this doctrine of a gradual transition has been
opposed by some living naturalists of high distinction, among
whom I may mention M.A. d'Orbigny and M. Agassiz. I have long
been convinced that we must abandon many of the identifications
formerly made of Eocene with recent shells; but some errors of
this kind do not affect the general reasoning on the subject. See
a discussion on this question, Quarterly Journ. of Geog. Soc.,
No. 5, p. 47 Feb. 1846.

[258] Darwin's Journal, p. 163. 2d. ed. p. 139.

[259] Journ. Roy. Geograph. Soc. vol. iii. p. 142.

[260] Book iii. ch. 50.

[261] Darwin's S. America, pp. 136, 139.

[262] Miller, Phil. Trans. 1851, p. 155.

[263] Phil. Trans. 1850, p. 354.

[264] Hooker's Himalayan Journal, ined.

[265] Ibid.

[266] See Manual of Geology, Index, _Rain-prints_.

[267] See Lyell on recent and fossil rains. Quart. Journ. Geol.
Soc. 1851, vol. vii. p. 239.

[268] Lyell's Second Visit to the United States, 1846, vol. ii.
p. 25.

[269] Encyc. Brit. art. _Rivers_.

[270] Sir T. D. Lauder's Account of the Great Floods in
Morayshire, August, 1829.

[271] Quarterly Jour. of Sci. &c. No. xii. New Series, p. 331.

[272] Culley, Proceed. Geol. Soc. 1829.

[273] Silliman's Journal, vol. xv. No. 2, p. 216. Jan. 1829.

[274] Silliman's Journal, vol. xxxiv. p. 115.

[275] See Lyell's Second Visit to the U. S. vol. i. p. 69.

[276] This block was measured by Capt. B. Hall, R. N.

[277] Inundation of the Val de Bagnes, in 1818, Ed. Phil. Journ.,
vol. i. p. 187, from memoir of M. Escher.

[278] Lib. viii. Epist. 17.

[279] When at Tivoli, in 1829, I received this account from
eye-witnesses of the event.

[280] Illustr. of Hutt. Theory, Section 3, p. 147.

[281] Quadro Istorico dell' Etna, 1824.

[282] The reader will find in my Travels in North America, vol.
i. ch. 2, a colored geological map and section of the Niagara
district, also a bird's-eye view of the Falls and adjacent
country, colored geologically, of which the first idea was
suggested by the excellent original sketch given by Mr. Bakewell.
I have r