My dear Wallace

I have finished y^r book; it seems to me excellent, & at the same time most pleasant to read.² That you ever returned alive is wonderful after all y^r risks from illness & sea voyages, especially that most interesting one to Waigiou & back.³ Of all the impressions which I have rec^d from y^r book the strongest is that y^r perseverance in the cause of science was heroic. Your descriptions of catching the splendid butterflies have made me quite envious, & at the same time have made me feel almost young again, so vividly have they brought before my mind old days when I collected, tho’ I never made such captures as yours. Certainly collecting is the best sport in the world. I shall be astonished if y^r book has not a great success; & your splendid generalizations on Geog. Distrib., with which I am familiar from y^r papers, will be new to most of your readers. I think I enjoyed most the Timor case, as it is best demonstrated; but perhaps Celebes is really the most valuable.⁴ I sh^d prefer looking at the whole Asiatic continent as having formerly been more African in its fauna, than admitting the former existence of a continent across the Indian ocean.⁵

Decaisne’s paper on the flora of Timor in which he points out its close relation to that of the Mascarene I.s supports y^r view.⁶ On the other hand I might advance the giraffes &c in the Sevalik deposits.⁷ How I wish some one w^d collect the plants of Banca! The puzzle of Java, Sumatra & Borneo is like the 3 geese & foxes: I have a wish to extend Malacca thro’ Banca to part of Java & thus make 3 parallel peninsulas, but I cannot get the geese & foxes across the river.⁸

Many parts of y^r book have interested me much: I always wished to hear an independent judgment about the Rajah Brooke, & now I have been delighted with y^r splendid eulogium on him.⁹

With respect to the fewness & inconspicuousness of the flowers in the Tropics, may it not be accounted for by the hosts of insects, so that there is no need for the flowers to be conspicuous. As according to Humboldt fewer plants are social in the tropical than in the temperate regions, the flowers in the former w^d not make so great a show.¹⁰

In y^r note you speak of observing some inelegancies of style, I notice none. All is as clear as daylight. I have detected 2 or 3 errata.

In vol 1. you write Sondiacus   is this not an error?¹¹

Vol 2. p 236 for Western side of Aru read Eastern.

p. 315 Do you not mean the horns of the moose? for the elk has not palmated horns.¹²

I have only one criticism of a general nature, & I am not sure that other geologists w^d agree with me: you repeatedly speak as if the pouring out of lava &c from Volcanoes actually caused the subsidence of an adjoining area; I quite agree that areas undergoing opposite movements are some how connected;¹³ but volcanic out bursts must I think be looked at as mere accidents in the swelling up of a great dome or surface of plutonic rocks,—& there seems no more reason to conclude that such swelling or elevation in mass is the cause of the subsidence, than that the subsidence is the cause of the elevation; which latter view is indeed held by some geologists.

I have regretted to find so little about the habits of the many animals which you have seen.

In Vol 2. p. 399 I wish I c^d see the connection between variations having been first or long ago selected & their appearance at an earlier age in birds of Paradise than the variations which have subsequently arisen & been selected. In fact I do not understand y^r explanation of the curious order of development of the ornaments of these birds.¹⁴

Will you please to tell me whether you are sure that the female Casuarius (Vol. 2. 150 sits on her eggs as well as the male; for if I am not mistaken Bartlett told me that the male alone, who is less brightly coloured about the neck, sits on the eggs.¹⁵

In Vol. 2 p. 255 you speak of male savages ornamenting themselves more than the women, of which I have heard before; now have you any notion whether they do this to please themselves, or to excite the admiration of their fellow men, or to please the women, or, as is perhaps probable from all 3 motives.

Finally let me congratulate you heartily on having written so excellent a book, full of thought on all sorts of subjects. Once again let me thank you for the very great honour which you have done me by your dedication

Believe me | My dear Wallace | Yours very sincerely | Ch. Darwin

Vol. 2. p. 455   When in New Zealand I thought the inhabitants a mixed race, with the type of Tahiti preponderating over some darker race with more frizzled hair; & now that the stone instruments reveal the existence of ancient inhabitants is it not probable that these Is^ds were inhabited by true Papuans. Judging from descriptions the pure Tahitians must differ much from your Papuans.—