Summary

Chapter 12 [of Variation] finished;

too late to include information on six-fingered men. Plans for book on man [Descent].

Mentions coral reefs of Tahiti.

Discusses volcanic islands; volcanoes of the Cordillera.

Summary

Discusses paper on volcanoes by J. W. Judd.

Comments on volcanoes of the S. American Cordillera.

Mentions paper by T. F. Jamieson ["Glacial period in N. Britain", Q. J. Geol. Soc. Lond. 30 (1874): 317–18].

Summary

Cites article by David Forbes dealing with the geology of the S. American Cordillera ["Geology of Bolivia and South Peru", Q. J. Geol. Soc. Lond. 17 (1861): 7–62].

Discusses the flexures of the Cordillera, the age of the mountains, and basaltic dikes in granite areas.

Summary

Discusses views of Daniel Sharpe on foliation and cleavage. Recalls his own previous discussion [in South America].

Summary

Remarks on fossils described in A. D. d’Orbigny’s Voyage dans l’Amérique méridionale.

Asks CL whether he has talked with John Murray concerning 2d ed. [of Journal of researches].

Mentions conversation with Hugh Cuming about South American shells. Has had G. B. Sowerby (elder) look at some specimens.

Summary

Discusses a proposed expedition to Australia. Urges collecting and investigating productions of isolated islands. Recommends dredging the sea-bottom.

Mentions keeping Helix pomatia alive in sea-water.

Summary

Takes "much to heart" solar evidence for short age of the earth. Cites evidence for "long endurance of our existing continents". Comments on process of denudation.

Summary

Mentions George Maw’s "good review" of Origin [Zoologist 19 (1861): 7577–611].

Relates remark by J. S. Mill concerning soundness of logic and method of Origin.

Is at work [on Orchids and Variation].

Summary

Has found a house on Baker Street to take for a month.

Mentions Daniel Sharpe’s study of the Grampians.

Association of various metamorphic rocks and relationship of their foliation to their dip and strike. Discusses foliation of schists and its origin. Comments on fluidity of gneiss and schists.

Summary

Remarks on his illness and treatment.

Discusses MS [of Coral reefs] and changes in his view of coral reefs since Journal of researches. Mentions C. G. Ehrenberg’s observations on coral reefs.

Summary

Discusses various types of coral reefs on which he has been collecting notes. Views of C. G. Ehrenberg. His conception of the formation of Bermuda.

Pessimistic about the effect of his poor health on his scientific work.

Summary

Satisfied that CD finds his conjectured rate of elevation and long periods of stasis reasonable, even if these periods cannot be estimated. Explaining upheaval by subterranean lava flow makes these pauses plausible. Suspects that mountainous areas move more than lowland and coastal areas. General upheavals or subsidence in Europe in glacial period are unlikely. Believes with Jamieson that there was glacial action in Scotland before its submergence and that it was equally mountainous then. Subterranean upheaval visits different countries by turn. Horizontal Silurian strata must have been submerged and upheaved. Rest has always been the general surface character. Believes, however, that the quantity of late Tertiary movement is against CD’s belief in the constancy of continents and oceans: perhaps since the Miocene period, but not since the Cretaceous.

Summary

To cast doubt on CD’s view that volcanic action is associated with elevation of land, CL suggests that local oscillations in strata underlying volcanoes could also explain how active volcanoes have uplifted fossil deposits of marine shells. Overall he is more inclined to believe that recent volcanoes belong to areas of subsidence rather than of elevation.

Summary

More comments on proofs [of CL’s Principles of geology, 10th ed.]. Discusses permanence of continents and other points.

Refers to passage describing evaporation of snow in Journal [of researches, pp. 277–8].

Cites astronomers’ views on increasing length of day.

Summary

Comments on investigation of coral reefs by A. A. Gould, particularly the reefs around Tahiti. Mentions description of reefs of Tahiti by W. Forbes.

Hooker’s view of work by C. J. F. Bunbury.

Summary

Asks CL to address a letter to Charles Maclaren.

Discusses recent publication by David Milne on erratic boulders [Edinburgh New Philos. J. 42 (1847): 154–172].

Views of Bernhard Studer on foliation of gneiss in the Alps. Asks CL to tell Leonard Horner of Studer’s views.

Summary

Discusses relationship of subsidence to the formation of coral reefs.

Summary

Galapagos land birds and reptiles.

No two naturalists agree on any fundamental idea [of species]. "Everything is arbitrary."

Has been with Richard Owen going over the S. American fossils.

Has worked out the non-relation between animals’ bulk and luxuriance of vegetation.

The horse once common on the Pampas. The mystery of the extinction of these animals.

Summary

Description and defence of his view of the tosca in Banda Oriental, along the Rio Uruguay and at the Rio Negro, taking issue with A. D. d’Orbigny. Refers to the pumice in the Patagonian Territory. Two tables show the layered tosca formation along the Uruguay.

Summary

CD forgets an author [CD himself in Coral reefs] "who, by means of atolls, contrived to submerge archipelagoes (or continents?), the mountains of which must originally have differed from each other in height 8,000 (or 10,000?) feet".

CL begins to think that all continents and oceans are chiefly post-Eocene, but he admits that it is questionable how far one is at liberty to call up continents "to convey a Helix from the United States to Europe in Miocene or Pliocene periods".

Will CD explain why the land and marine shells of Porto Santo and Madeira differ while the plants so nearly agree?