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.

Charles Darwin [CD] has not been absent from JDH's thoughts during the long break in their correspondence. He probably spoke too strongly about CD's species work & barnacles. speculates that CD was once prone to theoretical considerations about species & unaware of certain difficulties which JDH thought a more intimate acquaintance with species might clear up. Hence was pleased CD took up a difficult group like barnacles. CD's theories have progressed but JDH is not converted. He thought the transitions from one form to another in Sikkim would be more apparent. CD reasons rightly about JDH's Yangma valley; it is undoubtedly a vast moraine. He rejects the Himalayas as an independent chain of mountains & seeks the axis of the great mountain system between the Yarou river & the plains of India. He considers the glaciers of the Himalayan range unrivalled & is convinced they are receding. Explains that it is a double chain likes CD's Andes. [Thomas] Thomson [TT] & [Hugh] Falconer [HF] both regard the greatest Asiatic axis as a sub meridional one. The whole mountain system is incredibly complicated & he exceedingly doubt's Humboldt's system of six Mountain chains. Letter continues under date of 7 Apr. JDH now with HF at Honorable East India Company Botanic Gardens. HF had kept all his letters & overland parcels for five months due to insane procrastination but is now forgiven. HF's society is as ever delightful. HF no longer associates with the Asiatic Society. JDH received CD's Feb letter today & learned that the cold water system has done him much good but is not a cure, JDH sends congratulations on the Darwins' seventh child. JDH came to Calcutta [Kolkata] to persuade Jung Bahadur [JB] to let him travel in Nepal but JB cannot guarantee his safety while absent in England. JDH will therefore go instead to Sylhet then the Khassya [Khasia] Hills & Munnipore [Manipur] with [TT].

Thanks for the information about a possible investment.

Parcel from AAG containing cirripede specimens has been received by CD from Hugh Cuming.

Illustration of RF’s fossil cirripede specimens by J. de C. Sowerby.

CD wants Lepadidae drawings [for Fossil Cirripedia] harder, with lines of growth more distinct; he wants no shading or similarity to lithography, which he thinks has harmed natural history. He realises that mutilated specimens may make accuracy difficult.

Thanks AH for specimens of cirripedes. Believes all species of Lithotrya bore.

Requests permission to include foreign species in Fossil Cirrpedia (1851). Asks whether sponges arrived. Has not yet heard from Pearce about Pollicipes concinus.

Asks to borrow a cirripede specimen from collection of Frederick Dixon.

Discusses possibility of providing B. J. Sulivan with a vessel for fossil hunting in Patagonia.

Asks RO to ask Mrs Dixon about borrowing cirripede specimen.

Details of his continuing water-cure regimen.

The Palaeontographical Society will give him only one plate for foreign species. Work should stop until he knows how many will fit in. He must know what progress has been made.

Thanks him for additional fossil cirripede specimens.

Agrees to reduce rent on farm because of bad times.

Mentions AH’s ["On the boring of the Mollusca into rocks", Ann. & Mag. Nat. Hist. 2d ser. 2 (1848): 225–48]. Discusses anatomy and habits of Lithotrya.

Thanks JGF for geological information.

Steenstrup’s cirripede specimens have been of great use and interest. CD has now described 33 fossil pedunculated cirripedes.

Asks for whatever numbers, since 1845, of the Journal [of the Royal Geographical Society] he, as a Fellow, is entitled to receive gratis.

Describes progress in illustration of fossil cirripede specimens. Thanks for answers to questions. Comments on hermaphroditism. Describes his discovery of parasitic male cirripedes.

Encloses a letter from J. D. Hooker [see 1257], thinking that WJH would like to see it.

Urges dispatch on illustrations [for Fossil Cirripedia]; CD’s MS has been ready for some time and all depends on JdeCS. Suggests a way to hasten progress.