CD has suggested an explanation of how pike were introduced to a remote lake in Ireland by cormorants [carrying pike spawn on their feet or in their gullets].
Showing 41–60 of 274 items
The Charles Darwin Collection
The Darwin Correspondence Project is publishing letters written by and to the naturalist Charles Darwin (1809–1882). Complete transcripts of letters are being made available through the Project’s website (www.darwinproject.ac.uk) after publication in the ongoing print edition of The Correspondence of Charles Darwin (Cambridge University Press 1985–). Metadata and summaries of all known letters (c. 15,000) appear in Ɛpsilon, and the full texts of available letters can also be searched, with links to the full texts.
CD has suggested an explanation of how pike were introduced to a remote lake in Ireland by cormorants [carrying pike spawn on their feet or in their gullets].
Hybrid insects.
Description of the Salvages.
Variability of "transition groups" of insects; relation of variability to ranges of insects. The variability of wings, even within species. Reduction of flying ability on isolated islands.
Forbes’s "Atlantis" theory and insect fauna of the Atlantic islands, considered with regard to insect migrations.
Gives instances of sexual differences in the number of tarsi within species of Coleoptera and also variation in the number of tarsi between related species.
CD’s tabulation of colonists curious but explicable.
Working on Tasmanian flora; contemplating general essay on Australian distribution: Tasmania and Australia same alpine species; Swan River flora very peculiar and quite distinct from New South Wales.
Trying to establish new journal at Linnean.
Comparison of skulls of Ichthyosaurus and Cetacea.
JDH criticises C. J. F. Bunbury’s paper on Madeira [J. Linn. Soc. Lond. (Bot.) 1 (1857): 1–35].
Absence of Ophrys on Madeira suggests to JDH a sequence in creation of groups.
Why are flightless insects common in desert?
Australian endemism.
Responds to CD’s questions about mountain vegetation of the Cape of Good Hope. The distribution of some plants provides problems for both migration and special creation hypotheses.
Indigenous domestic animals of the New World.
Relationship of Newfoundland and Esquimo dogs to the wolf. Dogs like the Esquimo occur in Tibet and Siberia. Indian pariah dogs and jackals occasionally interbreed.
Describes domestic cats of India; reports cases of their interbreeding with wild cats. Wild cats are tamed for hunting.
Races of silkworm in India are crossed [see 1690].
Domesticated plants, fish, and birds of India.
Comments on local races and species of crows; it is impossible to trace a line of demarcation between races and species.
Variation in the ability of hybrids to propagate.
Indian cattle breeds; differences between Bos indicus and Bos taurus.
Is not satisfied that aboriginally wild species of horse and ass exist.
Believes all fancy breeds of pigeon originated in the East. Wild ancestors of pigeons, ducks, geese, and fowls. Interbreeding of wild species of pheasant.
[CD’s notes are an abstract of this letter.]
Has filled up CD’s paper [see 1674].
Distribution and relationships of alpine flora in U. S.
Reports that he sees the oxlip, cowslip, and primrose as really distinct species; hybrids are formed between any two.
Finds Forbes’s continental theories, migration, and double creation are all unsatisfactory explanations of geographical distribution of plants.
Is currently working on problems of sea transport of plant species.
European plants on Australian Alps only explicable by double creations.
Discusses hybrid plants he has raised, particularly hybrids between Geum urbanum and G. rivale, which are very fertile and exhibit great variability. [See Natural selection, p. 102.]
Red and white campions: JSH regards them as races, not species; a flesh-coloured intermediate exists.
Sends a list of "close" species from his Manual of botany.
Hopes Hooker or CD will write an essay on species. Discusses some of the difficulties of defining botanical species.
Answers queries on Azores fauna and flora.
Notes on the interbreeding of different races of silkworm. [Forwarded with explanatory note by Edward Blyth.]
Australian Leguminosae problem: of 900 species not ten are common to southwest and southeast. No migration; hence either creation or variation.
Himalayan thistles: graded intermediates between large and small English species, "shakes species to their foundations". Similarity of CD’s and his views on species.
Returns CD’s list of Azores plants with information on the distribution of the species added. Encloses a list, extracted from CD’s list, of those plants common to Europe and the Azores that were probably not introduced by man.
Discusses how best to simulate the light at a particular point on the earth’s surface using coloured glass; considers sunlight as composed of three "principles", varying in proportion according to latitude, which affect germination, lignification, and floriation.
Informs CD which colours of glass accelerate germination, lignification, and floriation; advises CD on obtaining such glass and offers his help in any experiments.