Informs CD of the effects of certain salts and other chemicals on animals.

Comments on CD’s results with Drosera. Suggests some experiments.

Wonders whether CD has any idea how the cuckoo manages to match its eggs to those of its host; believes it possible that the diet of the nestling cuckoo, which varies with its host, may affect its behaviour and the colour of its eggs.

Discusses role of insects in crossing varieties of Lathyrus odoratus and other species.

Comments on Hermann Müller [Die Befruchtung der Blumen (1873)],

and Anton Kerner ["Die Schutzmittel des Pollens", Ber. Naturwiss. Med. Ver. Innsbruck, 3 (1873): 100–68].

Admires FD’s work on anemophilous plants.

Would welcome JSBS visit to discuss Drosera. Nitrogenous fluids can act as ferments only if they act merely by exciting molecular movement in adjoining molecules.

Glass and cotton excite movement and cause cell contents to change visibly. Huxley coming to see this phenomenon.

Studied effect of poisons 12 or 15 years ago to see whether the action was similar to that on nervous tissue.

Is tired of inaction and so is leaving for Egypt and the East.

Confirms previous observations on ants [see 8788].

Sends his paper on fertilisation of the New Zealand species of the orchid Pterostylis [Trans. & Proc. New Zealand Inst. 4 (1871): 270–84].

Thanks for Dionaea.

George Bentham’s last Linnean Society [Presidential] Address [Proc. Linn. Soc. Lond. (1873): viii–xxix]. Admires it greatly.

CD’s recent work leads him to a different theory [from GB’s] on the separation of the sexes of plants.

Huxley has been at Down working with CD on Drosera – very helpful.

Thanks for the extract from the American paper.

Sends three lectures on the origin of human language [see 8962].

Although a "sincere admirer", he differs with CD on the relation of human to so-called animal language.

Leaves Wednesday with Huxley for holiday.

Family news.

He too thinks well of Bentham’s address.

Asa Gray elected Foreign F.R.S.

G. J. Allman is being proposed for Royal Medal by JDH and Huxley.

Thanks for sending WHF’s lecture, ‘On palaeontological evidence of the modifications of animal forms’ (Flower 1873).

Printed memorandum giving reasons why there should be subsidy on a large scale of scientific research unencumbered with teaching.

Has discussed with E. E. Klein about the purchase of a Hartnack microscope from Paris.

No summary available.

JDH asks William Thiselton-Dyer to inform Mr New whether or not he will be able to read JDH's paper on Kilimanjaro plants at the Linnean Society. JDH is leaving Beitrich for Gerolstein, & will then cross the Eifel to Altenahr & return home via Bonn or Aix. Mention's Kendall's death. JDH's tour has so far covered Luxembourg, Treves [Trier] & Berncastle [Bernkastel]. The weather has been cold & he has observed that the vegetation is not as far advanced as at RBG Kew & fruit & nut crops have been killed.

JDH clarifies that he is not the source of a request for Asa Gray to review his publication GENERA PLANTARUM. Especially as he is under the impression Gray would have nothing complimentary to say about his work on the order Rubiaceae, despite the effort JDH has put into & his belief that he has corrected more mistakes than he has made. He notes that [Sir William Turner] Thiselton-Dyer corrected the work before it went to press. JDH has just returned from a tour of the left bank of the Rhine, Eifel country [volcanic region of Germany], with his wife [Frances Hooker nee Henslow], [John] Lubbock & the Grant-Duffs. They also saw Luxembourg & Treves [Trier]. JDH has asked the publisher, Longman, to send Gray a copy of Decaisne & Le Maout [A GENERAL SYSTEM OF BOTANY DESCRIPTIVE AND ANALYTICAL]. JDH is currently working on the FLORA OF BRITISH INDIA with Thiselton-Dyer but they are hampered by shortcomings in [Carl Friedrich Philipp von] Martius' work & the illness of [Michael Packenham] Edgeworth & [Thomas] Thomson. [George] Bentham is currently working on Mimosaceae for Martius' work. A young man who works for Micheli, of Geneva, is at RBG Kew working on Onograceae & Rubiaceae. Bibb has sent RBG Kew a collection of Illinois plants. JDH hopes to go on holiday to the Auvergne with [Thomas Henry] Huxley. JDH also has much to do reforming business procedures at the Royal Society & arranging the Society's move to new apartments.