260 INVOLUTION [Chap. IV 



Letter 184 There was not much in last Natural History Review which 

 interested me except colonial floras 1 and the report on the 

 sexuality of cryptogams. I suppose the former was by 

 Oliver ; how extremely curious is the fact of similarity of 

 Orders in the Tropics ! I feel a conviction that it is somehow 

 connected with Glacial destruction, but I cannot " wriggle " 

 comfortably at all on the subject. I am nearly sure that 

 Dana makes out that the greatest number of crustacean 

 forms inhabit warmer temperate regions. 



I have had an enormous letter from Leo Lesquereux 2 

 (after doubts, I did not think it worth sending you) on Coal 

 Flora : he wrote some excellent articles in Silliman against 

 [my] Origin views ; but he says now after repeated reading 

 of the book he is a convert ! But how funny men's minds 

 are ! he says he is chiefly converted because my books make 

 the Birth of Christ, Redemption by Grace, etc., plain to him ! 



Letter 185 To J. D. Hooker. 



Down, Feb. 9H1 [1865]. 



I quite agree how humiliating the slow progress of man 

 is, but every one has his own pet horror, and this slow progress 

 or even personal annihilation sinks in my mind into insignifi- 

 cance compared with the idea or rather I presume certainty 

 of the sun some day cooling and we all freezing. To think 



1 Nat. Hist. Review, 1865, p. 46. A review of Grisebach's Flora of 

 the British West Indian /stands and Thwaites' Enumeratio Plantarum 

 ZeylaniiC The point referred to is given at p. 57 : " More than half 

 the Flowering Plants belong to eleven Orders in the case of the 

 West Indies, and to ten in that of Ceylon, whilst with but one exception 

 the Ceylon Orders are the same as the West Indian." The reviewer 

 speculates on the meaning of the fact " in relation to the hypothesis of an 

 intertropical cold epoch, such as Mr. Darwin demands for the migration 

 of the Northern Flora to the Southern hemisphere.' 1 



2 Leo Lesquereux (1806-89) was DOrn in Switzerland, but his 

 most important works were published after he settled in the United 

 States in 1848. Beginning with researches on Mosses and Peat, he 

 afterwards devoted himself to the study of fossil plants. His best 

 known contributions to Paleobotany are a series of monographs on 

 Cretaceous and Tertiary Floras (1878-83), and on the Coal-Flora of 

 Pennsylvania and the United States generally, published by the Second 

 Geological Survey of Pennsylvania between 1880 and 1884 (see L. F. Ward, 

 Sketch of Paleobotany, U.S. Geol. Sun 1 ., 5/// Ann. Rep. 1883-4; also 

 Quart. Journ. Geol. Soc. Vol. XLVL, Proe., p. 53, 1890). 



