Summary

Difference between sexes of Ibis rubra; change in plumage.

Summary

On the changes in plumage of scarlet ibis at the zoo in breeding season.

Summary

ARW’s wife will accompany him to Down.

Summary

He and another Bencher of Lincoln’s Inn have signed the necessary certificates for admission of CD’s son [George].

Summary

Asks CD to breakfast in London on Tuesday [24 Mar].

Summary

Accepts invitation.

Summary

Note identifying insects and remarking on stridulation.

Summary

On critical exchanges at the Linnean Society on natural selection and mimicry.

Roland Trimen’s paper on South African mimetic butterflies ["On some remarkable mimetic resemblances among African butterflies", Trans. Linn. Soc. Lond. 26 (1870): 497–523; read 5 Mar 1868].

Summary

Thanks for Variation.

Reports work on his travel book [The Malay Archipelago (1869)].

Summary

Lists stridulating organs of various Coleoptera.

Summary

On sounds produced by Euchirus longimanus beetle. Sends a pair by post.

Summary

On triumph of "Darwinianism".

Discussion of their differences on subject of protection.

Summary

The problem of sterility, and its relation to natural selection.

George Bentham’s support of Darwinism.

Summary

On sterility of natural species and natural selection. Closely allied forms from adjacent islands offer best chance of finding good species fertile inter se.

Problem of minute variations and sexual selection.

Summary

Notes the differences in seed production between cross- and self-fertilized flowers of Victoria regia.

Summary

Answers CD’s objection [see 6121 and 6146] about sexual differences and protective colouring. Summarises his theory of colour in nature.

Summary

If CD is not convinced by his notes on sterility, ARW has little doubt that he is wrong. In fact he was only half-convinced by his own arguments.

Modifies his first proposition [a species varies occasionally in two directions, but owing to free inter-crossing the variations never increase] and further discusses the subject.

Encloses Berthold Seemann’s notes on flora of the Hawaiian Islands. Presence of European alpine species in Hawaiian volcanoes is a "hard nut" for geographical distribution [but see ARW’s Island life (1880), p. 323].

Summary

Coloration of butterflies; brilliantly coloured females.

Commends CD on his paper on specific differences in Primula [J. Proc. Linn. Soc. Lond. (Bot.) 10 (1869): 437–54; reprinted and revised in Forms of flowers] as a test-case proving origin of real species.

Summary

Bibliographical references on [stridulation in] Coleoptera. Finds no idea of sex has occurred to authors [i.e., they do not find the stridulating organs differing according to sex; cf. Descent 1: 378–85].

Summary

Returns George Darwin’s criticisms of his notes on sterility and sends further notes in reply. Since there are degrees of sterility between varieties, "is it not probable that natural selection can accumulate these variations?" Varieties that are adapted to new conditions could then survive and form new species without being isolated.