Thanks for Variation.
Reports work on his travel book [The Malay Archipelago (1869)].
Showing 1–17 of 17 items
Thanks for Variation.
Reports work on his travel book [The Malay Archipelago (1869)].
Responds to CD’s queries on polygamy in birds and orang.
Discusses sexual selection and secondary characters; colours and sexual preference.
Expresses his admiration for Pangenesis; it is superior to Herbert Spencer’s theory.
ARW differs somewhat with CD’s chapter on causes of variability [ch. 22 in Variation]. Thinks several of CD’s arguments are unsound.
Briefly discusses how natural selection might aid in producing sterility between allied species.
Offers enclosure demonstrating that natural selection could produce sterility of hybrids.
More on Pangenesis and the inadequacy of H. Spencer’s approach.
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].
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.
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.
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.
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].
Various topics related to sexual selection: sexual differences, sexual preferences, coloration.
Answers CD’s objection [see 6121 and 6146] about sexual differences and protective colouring. Summarises his theory of colour in nature.
The problem of sterility, and its relation to natural selection.
George Bentham’s support of Darwinism.
On triumph of "Darwinianism".
Discussion of their differences on subject of protection.
Accepts invitation.
ARW’s wife will accompany him to Down.
On sounds produced by Euchirus longimanus beetle. Sends a pair by post.
Submits a 15–point argument against CD’s views on the coloration of female birds and insects.
Sexual differences in coloration. Sexual selection versus natural selection as explanations. ARW continues to argue against sexual selection, saying that natural selection, in keeping the female dull for protection, would account for differences in sexual colouring more effectively than inheritance and partial transmission of sexually selected male colours. Colours of female birds of paradise. Protective coloration. Disagrees with CD on coincidence of hidden nests and bright colours of females.