Supports, in his orchid paper, CD’s view that sterility occurs at random [Trans. Bot. Soc. Edinburgh 7 (1863): 543–50].

Cannot get his Drosera paper published [abstract in Edinburgh New Philos. J. 2d ser. 17 (1863): 317–18].

Thanks CD for two letters and his portrait.

CD’s book [Orchids] opened up terra incognita for him.

His work on S. African butterflies continues.

Reports on a moth that punctures peach skins.

Interesting that thoughtful naturalists are forced to admit mutability of species.

Some notes on Oxalis.

Sees difficulties in adhering to the concept of design in nature.

Is surprised at Hooker’s and Daniel Oliver’s ignorance regarding spontaneous movements of tendrils.

CD should continue his work on climbing plants, "it will be fruitful in your hands".

JDH explains why he cannot take Scott on at Kew.

John Tyndall cannot answer CD’s questions on glaciers. Edward Frankland’s ignorance. In JDH’s opinion, heaviness of winter snowfall is the greatest element in size of glaciers and this is a function of low mean temperature. Discusses descent of glaciers.

Encloses drawings of Menyanthes and Pulmonaria anthers.

Sends Passiflora paper [see 4485].

Sends seeds of peloric Antirrhinum crossed by normal form and sends results of his experiments [table of crosses].

Discusses CD’s and Mrs Gray’s health.

Comments on some climbing plants.

Praises Wallace’s article applying natural selection to man ["The origin of human races", J. Anthropol. Soc. Lond. 2 (1864): clviii–clxxxvi].

Discusses the reported sterility of the flowers of Voandzeia and Amphicarpaea.

Feels the ending of slavery is worth the cost of the Civil War.

Forwards a letter from his head brewer, Laurence Burleigh, on yeast. They seldom exchange yeast with other brewers, and he doubts whether weak yeast from one brewery will ferment strongly in another.

Congratulates CD on the Copley Medal.

Is making inquiries on the habits of American cuckoos and sends a letter from Henry Bryant on that subject.

Discusses the Civil War.

Encloses letter from W. H. Leggett containing observations on Amphicarpaea.

Sabine’s address, printed in the Reader [4 (1864): 708–9], is good on the whole. Sends Huxley’s account of the row.

Praises John Ruskin’s eloquent reply to Jukes.

Discusses several subjects, including examples of "Unity of coloration",

the origin of gall-producing poison,

Wagner’s theory of viviparous larvae,

and stridulation in insects.

Sends a reference supporting CD’s statement in Origin that flies check propagation of horses and cattle.

Assures CD of his belief in descent from his first reading of Origin.

Describes a case of dichogamy.

Discusses dimorphism of Oxalis; one form has 99% sterile anthers. Has found three kinds of fertile anthers.

Sends his observations on sterility of Eschscholzia,

on Oxalis,

and on recently found dimorphic plants.

Sends specimen of Hedyotis [see Forms of flowers, p. 133].

Position as Curator allows no time for experiment.

Describes plans for vast new layout of Calcutta Botanic Garden according to natural orders.

Himalayan and Scottish plants are doing well.

Hopes to experiment on temperate plants in tropics, to test CD’s views of migration during glacial periods.

Sends observations on acclimatisation of English cultivated plants.

Leersia CD sent are growing and fertile.

Observations on Ophrys plants and Thymus vulgaris. Encloses sketch of different forms of T. vulgaris [see Forms of flowers, p. 302].

Cites cases of difference in coloration between the sexes of some species of Crustacea, annelids, and spiders.

Discusses dimorphic plants and self-sterility.

Outlines some experiments involving the crossing of different species of orchids.

Encloses extract from Carl Claus, Die freilebenden Copepoden [1863].

Asks whether his former pupil, J. J. Moulinié, might translate Variation into French for Reinwald. CV would provide a preface. Encloses letter from Moulinié to Reinwald.

Supposes that infants’ eyes bulge and become engorged with blood during fits of sneezing or screaming, but doubts Charles Bell’s experiment of opening and observing eyes turn from pale to red [Anatomy and philosophy of expression (1844)].

Discusses the action of the eye when looking at distant objects.

Sends CD cheque for £250, two-thirds of the profits on the sale of 700 copies of Origin, 4th ed.

Hopes he has found a suitable indexer for Variation.