weight to the physicists, seeing how Hopkins, Hennessey, Haughton, and
Thomson have enormously disagreed about the rate of cooling of the crust;
remembering Herschel's speculations about cold space (382/1. The reader
will find some account of Herschel's views in Lyell's "Principles," 1872,
Edition XI., Volume I., page 283.), and bearing in mind all the recent
speculations on change of axis, I will maintain to the death that your case
of Fernando Po and Abyssinia is worth ten times more than the belief of a
dozen physicists. (382/2. See "Origin," Edition VI., page 337: "Dr.
Hooker has also lately shown that several of the plants living on the upper
parts of the lofty island of Fernando Po and on the neighbouring Cameroon
mountains, in the Gulf of Guinea, are closely related to those in the
mountains of Abyssinia, and likewise to those of temperate Europe." Darwin
evidently means that such facts as these are better evidence of the
gigantic periods of time occupied by evolutionary changes than the
discordant conclusions of the physicists. See "Linn. Soc. Journ." Volume
VII., page 180, for Hooker's general conclusions; also Hooker and Ball's
"Marocco," Appendix F, page 421. For the case of Fernando Po see Hooker
("Linn. Soc. Journ." VI., 1861, page 3, where he sums up: "Hence the result
of comparing Clarence Peak flora [Fernando Po] with that of the African
continent is--(1) the intimate relationship with Abyssinia, of whose flora
it is a member, and from which it is separated by 1800 miles of absolutely
unexplored country; (2) the curious relationship with the East African
islands, which are still farther off; (3) the almost total dissimilarity
from the Cape flora." For Sir J.D. Hooker's general conclusions on the
Cameroon plants see "Linn. Soc. Journ." VII., page 180. More recently
equally striking cases have come to light: for instance, the existence of a
Mediterranean genus, Adenocarpus, in the Cameroons and on Kilima Njaro, and
nowhere else in Africa; and the probable migration of South African forms
along the highlands from the Natal District to Abysinnia. See Hooker,
"Linn. Soc. Journ." XIV., 1874, pages 144-5.) Your remarks on my regarding