On the suggestion of Jeffries Wyman, he writes about the rats that he captured in Mammoth Cave in 1850. They were indeed blind. Reginald Mantell studied them and learned that with long exposure to graduated light, they became somewhat sensitised. Sends copy of an abstract which he wrote as a letter to A. H. Guyot ["On the Mammoth Cave of Kentucky", Am. Journal of Sci. and Arts 2d ser. 11 (1851)]. [See 3007.]

Sends CD passages from A. S. Taylor’s book [On poisons in relation to medical jurisprudence and medicine, 2d ed. (1859)], citing smallest portions of poisons that are chemically detectable. "Drosera beats the chemists hollow."

Observations on his white blue-eyed cat. There is no sign of deafness.

Apropos of ch. 5 of Origin, tells of blind rats found when a Roman bridge was excavated.

Explains discrepancies in weights and measures caused by changes since 1836 in apothecaries’ measures.

EC has found that a discrepancy in A. W. von Hofmann’s experiments with iodine solutions resulted from an error in Hofmann’s use of decimals.

Reports S. P. Woodward’s opinion of the Origin: "a very sad book, it unsettles all one’s religious principles and the worst of it is so much of it is true".

Sends the tithes.

Sends weights of three objects (blotting paper, thread, and hair) to within 1/1000 of a grain.

Discusses the possibility of a land-bridge connecting Biscay with Ireland and the consequent occurrence in southern Ireland of Asturian plants which are absent from England.

Asks if Hooker or anyone has criticised Edward Forbes’ botanical migration of five floras in the British Isles ["On the connexion between the distribution of existing fauna and flora of the British Isles, and the geological changes which have affected their area", Mem. Geol. Surv. G. B. 1 (1846): 336–432].

Dr Hooker has given him CD’s memorandum on the fly-catcher.

Copies out extract from Curtis’ Botanical Magazine [On Apocynum androsæmifolium, 8 (1794): tab.]: 280 and gives a further reference in Erasmus Darwin’s The loves of plants [1789]. Suggests that they look at Apocynum.

CL has calculated that elevation and subsidence of certain formations in Sweden and Norway take place at the rate of 2 1/2 feet per century. He now proposes to estimate the age of a bed by including a conjecture that pauses occur in the oscillations in the ratio of 4 periods of stasis to one of movement. Applying this formula to Scotland, the last subsidence and re-elevation would be 590,000 years and the age of the beds with human implements would be 20,000 years.

Encourages CD’s work in vegetable physiology.

Ascending the Lebanon JDH noted limits of plant distribution as CD requested: lower limits of a genus sharper than upper. Sharpness of boundaries related to a plant’s moisture requirement.

Impressed by "sporadic" distribution at the Jardin des Plantes in Paris.

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.

Gives an extract from L. von Buch on the flora of the Canaries [Physikalische Beschreibung der Canarische Inseln (1825)].

Natural selection does not explain why animals of different groups in the same place often resemble each other.

JDH’s page-by-page criticisms on Origin, first edition, as requested by CD for preparation of the third edition.

Discusses Origin, suggesting confirmation might come from studying reproduction in microscopic organisms.

Gives anecdotal observations of blind rats and white cats.

Glacial action in the Andes.

Origin of Chilean sheep.

Varieties of S. American horses.

Would be glad to have Chauncey Wright’s [Origin] review for the Natural History Review.

Response to [3020]. CD has been misled by errors made in the Times notice [5 Dec 1860, p. 5]. GCW does not doubt that Foraminiferous matter as well as other deep sea deposits vary greatly in thickness, but positive results are difficult to establish. Some areas of the sea bed are bare but their extent has not been established. He now thinks that he was too hasty in the conclusion that deep currents produce abrasion and rounding of gravel.

Charlotte [Wedgwood Langton?] reports from Mr Wallis on time of day that sundew opens.

CD’s article worth publishing in Gardeners’ Chronicle. JDH interprets CD’s observation in terms of selection. Has observed similar phenomenon in Cruciferae, where it can be taxonomically important.

Gives observations on the habits of the "agricultural ant" of Texas.