Thanks RT for his letter and MS.

Is astonished by the different forms of orchids he describes.

Urges RT to describe and experiment with two or three of the more distinct genera.

"I believe, or am inclined to believe in one or very few primordial forms, from community of structure and early embryonic resemblances in each great class."

Further discusses RT’s observations on Cape [of Good Hope] orchids and asks whether it would be possible for him to send some specimens to Kew.

RT has sent his observations on orchids to CD. Has found only one case of an insect with a pollinium adhering to it.

CD has drawn up a paper from RT’s orchid notes on the fertilisation of Disa grandiflora for the Linnean Society [J. Linn. Soc. Lond. (Bot.) 7 (1863): 144–7].

CD would welcome seeds of any Cape Oxalis for his investigation of dimorphism.

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.

Discusses methods of pollination in orchids.

Thinks RT should investigate Physianthus to see if it requires insect aid for fertilisation as the Asclepiadaceae do.

Comments on CD’s paper on Linum [Collected papers 2: 93–105].

Sends specimens of dimorphic and trimorphic Oxalis.

Comments on H. W. Bates’s work [Naturalist on the river Amazons].

CD’s doctor [J. M. Gully] has ordered him to do nothing for six months.

Thanks RT for orchid specimen.

Dares not look at Oxalis flowers.

Regrets RT cannot get seed, especially from his trimorphic flowers.

Asks for bulbs of two or three forms.

Oxalis plants have arrived safely [see 4347].

CD regrets his mistake about Disa; will correct it.

Thanks RT for his additional facts about Disa.

Is recovering slowly from ten months’ illness.

Asks whether Strelitzia reginae grows in gardens at the Cape. Suspects it must be fertilised by a bird.

Has forwarded RT’s paper on Bonatea to the Linnean Society [J. Linn. Soc. Lond. (Bot.) 9 (1865): 156–60].

The Oxalis sent by RT flowered but CD has made out only two forms; he thinks there ought to be three, so would welcome more seed.

Butterflies of Mauritius.

RT’s Bonatea paper published by Linnean Society [J. Linn. Soc. Lond. (Bot.) 9 (1867): 156–60].

Invites RT to come to Down for a week-end.

On ocelli.

Sexual differences and proportion of sexes in butterflies.

Coleoptera.

[See Descent 1: 310; 2: 132.]

CD seeks information on the variation of ocelli within species of butterflies.

Variations in the ocelli of Lepidoptera.

Encloses six pages from his catalogue of S. African butterflies [Rhopalocera Africae australis, 2 pts (1862, 1866)].

Thanks RT for drawings of ocelli, especially for the description of ocelli of S. African Saturniidae. Would like to know of any cases in which the ocelli are confined to the male, to illustrate better the case of the peacock.

Sends prospectus of forthcoming work by his brother [Henry Trimen] and W. T. Thiselton-Dyer [Flora of Middlesex (1869)]. Hopes CD will subscribe.

Is interested in the relative numbers of males and females of all animals; wants any instances of males, or females, being in excess.

Proportion of sexes in butterflies; discussion of subject at meeting of Entomological Society, London.

Attraction of males by female Lasiocampa quercus. [see Descent 1: 311–12.]

RT’s argument about the Lasiocampa strikes him as very good; asks for any similar cases. Wonders whether male butterflies may serve more than one female.