Summary

Discussion of Mrs Agassiz’s letter [to Mary Lyell, forwarded to CD] regarding S. American glacial action,

with comments on Bunbury’s letter on temperate plants.

Refers to opinions of Agassiz, David Forbes, Hooker, and CD on glacial period and glaciers.

Wishes he had published a long chapter on glacial period [Natural selection, pp. 535–66] written ten years ago.

Tells of death of his sister, Catherine, and other family matters.

Summary

Inquiries on effect of dry heat on temperate plants for glacial chapter.

Summary

Responds to JDH on history of plant geography.

Opinion of Humboldt.

Origin of higher phanerogams.

Importance of the occurrence of south temperate forms in the Northern Hemisphere.

Summary

CD finds JDH’s objections to a mundane cold period significant, and he endeavours to show how they do not rule out mutability.

He is writing on crossing.

Summary

Species migration since the Pliocene. Effect of the glacial epoch. Present geographical distribution, especially similarities of mountain floras, explained by such migration; mountain summits as remnants of a once continuous flora and fauna.

Cross-fertilisation in Fumariaceae.

Summary

Comments on letter from Georg Hartung to CL dealing with erratic boulders.

Discusses migration of plants and animals.

A letter from Thomas Thomson on heat endured by temperate plants.

Summary

Argument, based on geographical distribution and competition, for a mundane glacial period rather than cooling of one longitudinal belt at a time.

Summary

Asks whether Crustacea from temperate parts of the Southern Hemisphere are more strongly analogous to those in same latitudes of the Northern Hemisphere than are Arctic to Antarctic Crustacea.

Discusses astonishing finds of mammalian and reptilian remains in Purbeck beds; notes reactions of Lyell.

Has doubts about Richard Owen’s recent classification of mammals [J. Proc. Linn. Soc. Lond. (Zool.) 2 (1858): 1–37].

Works away [on Natural selection].

Asa Gray has given valuable assistance.

Summary

"Climbing plants" sent off.

Encourages JDH to include notes on gradation of important characters in Genera plantarum or to write a paper on the subject. Has given prominence to gradation of unimportant characters in climbing plants. Believes that it is common for the same part in an individual plant to be in different states. Same may be true of important parts – for example position of ovule may differ.

Two articles in last Natural History Review interested him; "Colonial floras" [n.s. 5 (1865): 46–63]

and "Sexuality of cryptogams" [n.s. 5 (1865): 64–79].

Fact of similarity of orders in tropics is extremely curious. Thinks it may be connected with glacial destruction.

Leo Lesquereux says he is a convert for the curious reason that CD’s books make birth of Christ and redemption by grace so clear to him!

"Not one question [for JDH] in this letter!"

Summary

Thanks CL for Hooker’s letter.

Discussion of Hooker’s views on glacial action and temperature with specific reference to S. America.

His squabbles with Hooker on transport of seeds via water currents,

temperate plants, and preservation of tropical plants during cooler period.

Expresses interest in seeing Agassiz’s letter.

Summary

Asks for any authentic cases of "sports", which CD calls "bud-variations". Flowers introduced from warmer temperate regions are said to be particularly apt to sport in this way.

CD now has proof that Cinchona is dimorphic and that some dimorphic plants are absolutely sterile with their own-form pollen.

Asks GHKT to examine or send pollen specimens of two Ceylon genera.

Summary

Comments on Huxley–Falconer dispute [see "On the method of palaeontology", Ann. & Mag. Nat. Hist. 18 (1856): 43–54].

Wollaston’s On the variation of species [1856].

Has exploded to Lyell against the extension of continents.

Plants common to Europe and NW. America as result of temperate climate.

Summary

Comments on the great extent of variations and on the acknowledgment of the new idea of greater female variety.

Expresses belief that the glacial period did affect the tropics, though HWB’s arguments have confounded him.

Poses a series of questions concerning sexual selection.

Summary

An enclosure sent with the letter to JDH, 14 November [1858] (Correspondence vol. 7) - questions and comments on lists of European species found in south-west Australia and Tasmania, and European genera found in Australia.

Summary

Sorry to hear of JDH’s household troubles.

Will try to get a couple of flowers of Leschenaultia to send him.

"What a good case that of the Cameroons"; the 4000ft [elevation] is much to CD’s "private satisfaction".

Sends JDH a copy of Orchids.

Summary

High praise and detailed comments on JDH’s introductory essay to Flora Tasmaniae, which CD has now finished reading.

Disagrees on power of transoceanic migration. Advocates glacial transport of plants.

CD’s response to reviews of Origin in Saturday Review [8 (1859): 775–6] and John Lindley’s in Gardeners’ Chronicle [but see 2651].

Summary

Thanks for letter and "valuable" extracts.

If S. American Carabi differ more from other species than do those from other distant locations (e.g., Siberia, Europe, etc.), CD agrees that difference would be too great to have occurred in the recent glacial age; CD also rejects independent origin. Plants seem to migrate more readily than animals. HWB should not underrate length of glacial period; CD also believes they will be driven to an older glacial period.

Sorry about news of British Museum – hopeless to contend against anyone supported by Owen.

CD dearly wishes HWB could find a situation in which he could give time to science.

Summary

CD defends his view of land birds on St Helena.

Explains why he would not expect American plants on the Azores.

It makes him miserable that he and JDH look at everything so differently.

Summary

Comments on glaciers in North America.

Asks if glacial periods have occurred alternately in the Northern and Southern Hemispheres. Relevant to his glacial discoveries in South America: "it would have been an immense relief to my mind if I could have assumed … this". CD wishes to discuss subject in new edition of Origin [5th].

Summary

Returns book with thanks. "Joyfully accepts" idea of the warming of Southern Hemisphere during glacial period in the Northern. Lyell is unwilling.

Mentions H. N. Moseley’s study of descent of glaciers [Proc. R. Soc. Lond. 17 (1869): 202–8].

CD greatly troubled by problem of age of the earth and calculations of Sir William Thomson. Asks about changes in the form of the globe.