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Showing 21–40 of 616 items
No summary available.
Sends list of plants with asymmetry in nectar-secreting surfaces and pistils bent in that direction. Shows insect agency so important that structure has changed. Asks for contrary or confirming examples and that request be passed on to Daniel Oliver.
Has examined Leschenaultia and concludes the external viscid surfaces have nothing to do with the stigmatic surface. Agrees with CD’s style and nectary conclusions; accounts for their form and position in irregular flowers by describing floral development.
[Enclosed are some queries by CD with answers by JDH. Gives information on seed setting by Mucuna
and an opinion on the abruptness of N. and S. limits of plant ranges.]
JDH has settled the Leschenaultia case, but it remains a difficulty to CD.
Goodenia, like bee orchid, seems a case of a structure with an evident function, which is not carried out. Is curvature of styles an incidental result of growth or a pollination adaptation?
No summary available.
To understand Leschenaultia pollination CD requires field observations in the native country.
Has observed two forms of cowslips, which he calls male and female. The same two forms are found in primroses.
Describes Sedgwick’s attack on CD’s views [at Cambridge Philosophical Society] and his own defence, though he believes CD has pressed his hypothesis too far.
No summary available.
CD’s divergent series explains those anomalous plants that hover between what would otherwise be two species in a genus.
Inclined to see conifers as a sub-series of dicotyledons that developed in parallel to monocotyledons, but retained cryptogamic characters.
Mentions H. C. Watson’s view of variations.
Man has destroyed more species than he has created varieties.
Variations are centrifugal because the chances are a million to one that identity of form once lost will return.
In the human race, we find no reversion "that would lead us to confound a man with his ancestors".
Dissection of Leschenaultia convinces CD insect agency necessary for self-fertilisation in this case.
Primroses and cowslips seem universally to occur in two forms. Very curious to see which plants set seed.
J. S. Henslow’s defence of CD;
[Thomas?] Thomson’s opposition to Origin.
Instructs JDH on how to pollinate Leschenaultia.
Evidence of Leschenaultia and the dioecious condition of cowslips and Auricula is making necessity of insect pollination "clear and clearer".
Lyell, de facto, first to stress importance of geological changes for geographical distribution.
Asa Gray has given CD too much credit for theories of geographical distribution.
Reaction to hostile criticism
and debt to Lyell, Huxley, JDH, and W. B. Carpenter.
Floral anatomy.
Wallace’s capital response on reading Origin.
E. W. Binney has published on coal-plants living in marine waters ["On the origin of coal", Mem. Lit. & Philos. Soc. Manchester 2d ser. 8 (1848): 148–94], an old CD idea.
Waste of pollen in horse chestnut will make a good case against perfection.
Convinced selection is the efficient cause. Less convinced of physical causes than JDH because he sees adaptation everywhere and that must be due to selection.
Harvey’s letter to JDH more accepting of natural selection than CD expected.
Battle over Origin is raging in the United States.
Weary of hostile reviews.
Doubts about going to Oxford [for BAAS meeting].
CD’s response to criticism of natural selection. Exasperated at not being understood. He tries to narrow the gap between himself and JDH.
Floral anatomy of Goodeniaceae: although flowers seem to fertilise themselves by pistil moving to anther, CD shows that insect agency is necessary. Wants JDH to check his interpretation of stigmatic surface.
Glad to hear good news of Etty [Henrietta Darwin].
CD’s observations on Scaevola are capital. The indusium collects the pollen and is the homologue of the pollen-collecting hairs of Campanula. A boat-shaped organ forms a second indusium, the inside base of which forms the stigmatic surface. The latter later protrudes as horns, forming the stigma.
Describes W. H. Harvey’s scientific career and thinks his letter interesting. Agrees with Harvey that the primary agency of natural selection is as great a mystery as ever. [Response to 2823.]
Progress of [Thomas?] Thomson and G. H. K. Thwaites on accepting mutability.
Bee orchid pollination.
JDH has written to CD on homologies of stigma in Goodeniaceae.