Though correspondence has never ebbed so low, CD is constantly in his thoughts.

Observations on cheetahs used as domesticated hunting animals.

Finds geographical barriers sometimes separate species, but also finds species that remain separate where there are no barriers to migration.

Colour "individuates" isolated animal species.

Plains and alpine animal distribution show altitude not strictly analogous to latitude.

Impact of timber cutting on climate has led to extinction of crocodiles.

Will discuss coal formation in letter to Edward Forbes.

CD often asked whether isolated mountains in southern latitudes had closely allied representatives of Arctic and north temperate plants; JDH has found a representative barberry.

Making for Darjeeling via Calcutta.

Brian Hodgson reading CD’s Journal of researches with delight.

Forwarding breeding pamphlets.

JDH recommends P. S. Pallas on degeneration.

CD’s facts on sex in barnacles startling.

Hugh Falconer’s health.

Hugh Falconer’s misbehaviour.

Waiting out rains at Brian Hodgson’s.

Will make botanical transverse section of Himalayas from plains to snow.

Arrangements to pass Sikkim Rajah’s territory.

No evidence of glacial or diluvial action in sub-Himalayan mountains. No evidence of detrital coal formation.

Hodgson’s replies to CD on introduced species and hybrids.

Physical description of Sikkim mountains.

Travelling through Kinchin snows.

Transported boulders.

Continues prior letter of this date. Has received CD’s [1202]. Thanks CD for saving his correspondence.

Sent "a yarn about species" in October mail.

Some "puerile" JDH letters printed in Athenæum.

Requests CD extract anything valuable from his letters to CD and Lyell for Athenæum.

CD’s complemental males in barnacles wonderful.

Warns CD to drop his battle about perpetuity of names in species descriptions.

Pleasure at receiving CD’s scientific letters to JDH and Hodgson.

The H. Wedgwoods’ pecuniary loss.

Condolences at CD’s father’s death.

Rajah harasses JDH’s work. Lack of supplies, rain, malarial valleys, and landslips make going difficult. Cannot get into Tibet.

"Twenty species [of plants] here [Camp Sikkim] to one there [Tierra del Fuego?] always are asking me the vexed question, ""where do we come from?""."

From observation of terraces descending to steppes and plains of India, he thinks that the Himalayas were once a grand fiord coast.

Has information CD requested on Yangsma valley. JDH’s detailed hypothesis of origin of dam there. Does not agree with CD’s interpretation.

CD partly right. JDH was calling "stratification" what CD calls "foliation". Answers CD’s question on cleavage foliation in Himalayas. Glacial action.

Charmed by CD’s Admiralty instructions on geology [in Manual of scientific enquiry (1849), Collected papers 1: 227–50], but complains he does not give prices of books and instruments he recommends.

Spoke too harshly about CD’s involvement in nomenclatural reform.

JDH used to think CD "too prone to theoretical considerations about species", hence was pleased CD took up a difficult group like barnacles. CD’s theories have progressed but JDH not converted. Sikkim has not cleared up his doubts about CD’s doctrines.

Argument with Falconer.

Falconer’s misbehaviour.

Geology of Khashia [Khasi] mountains. Speculations on mountain building and origin of Himalayas.

Returns Asa Gray’s letter. Disappointed with Gray. Comments on America. British–American relations.

J. H. Balfour gives Scott excellent character reference, but says he is unfit either to superintend or be subordinate.

Herbert Spencer’s review of J. M. Schleiden is interesting [see 4457].

CD’s photograph looks like J. R. Herbert’s Moses in the fresco in the House of Lords.

JDH is delighted about oxlip, but hybridity does not explain some large patches that are uniform and do not vary towards either cowslip or primrose.

Encloses letter from W. H. Harvey discussing Myosotis sylvatica and the common dandelion.

Recounts row at the Royal Society over exclusion of mention of Origin from Sabine’s address awarding Copley Medal to CD.

Encloses two letters to JDH from James Hector in New Zealand.

Forwards H. T. Stainton letter for reply.

Finds many Cucurbita have tendrils with sticking ends.

The "potentiality of so many organs in plants to play so many parts is one of the most wonderful of your discoveries . . . one day it will itself play a prodigious part in the interpretation of both morphological and physiological facts".

Is disgusted with Sabine’s address [see 4708] because of its mutilation of what JDH wrote.

THH’s slashing leader in Reader ["Science and ""Church policy"" ", 4 (1864): 821] – as usual he destroys all in his path.

Encloses letter from G. H. K. Thwaites with a message for CD [see encl].

Lyell wants to see JDH’s last letter [the part on glacial periods]. Lyell full of concern about astronomical causes of heat and cold on the globe.

Encloses letter from John Scott.

More on Naudin’s hybrid; the wonder lessened slightly.

JDH’s view that insular plants [distantly] related to those of continents are common came to him only after the lecture was in print; has not yet thought it out fully.

Moroccan flora may throw some light on Madeira flora.

Cannot come to Down; John Smith is unwell.

Will go to Paris again at end of month.

Wallace and F. J. H. von Mueller of Victoria are most likely candidates for Royal Society Gold Medal for biology.

Encloses letter from Henry Barkly.

Amazed that Hugo von Mohl and E. M. Fries are not foreign members of Royal Society; Thomson going over the whole matter.

Candolle’s contribution to botany.

Lubbock shocked about Wollaston.

CD’s answer to Greg was capital.

Comments on Variation.

Charles Murchison’s work on Falconer’s Memoirs [Palaeontological memoirs and notes of the late Hugh Falconer (1868)] and JDH on Falconer.

FM much gratified by the appearance of Für Darwin translation.

Discusses dimorphism in Rubiaceae.

Sends enclosure [a letter from Lady Lyell?]. He is choking with vanity.

Is going to send Willy to Mr La Touche in Salop; he brought up young Colenso and Frank Lyell. Some of his friends will think he is sending his son into a nest of young adders!