CD is mistaken in considering Acropera unisexual, with only male flowers [Orchids, pp. 203–10]. JS has successfully fertilised two A. loddigesii flowers. One is ripening. Dissection of the other shows the pollen accomplishes fertilisation without contacting any stigmatic surface. Abortive ovules found in flowers that did not become fertilised when pollinated. JS suggests Acropera has both unisexual male and hermaphrodite flowers.

Discusses whether or not "male" Acropera bear fruit. JS’s interpretation of Acropera pollination is ingenious. Pollen-tubes of some cleistogamous flowers germinate in the anthers.

Appreciates CD’s acknowledging his letter and his comments on Acropera. Will send CD the Acropera capsule which is now maturing.

Experimenting on vegetable parthenogenesis.

Structure of Acropera.

Praises JS’s experimenting.

Has he ever studied the relative fertility of varieties? CD very interested in this subject.

Discusses Acropera.

Wants to quote JS on Zea [Variation 1: 321].

CD sends his Primula paper [Collected papers 2: 45–63].

JS does not fully accept natural selection.

Has never raised oxlips from cowslips or primroses; reports of such must be cases of crossing.

Discusses relative fertility of varieties, self-fertility of hybrids, and plans for experiments on enhanced hybrid fertility.

JS’s facts on Primula are new to CD.

In Linum CD has also found dimorphic and non-dimorphic species.

Plans to publish next autumn on successive homomorphic generations in Primula.

"Fluctuating forms" due to culture.

Urges JS to publish.

Lobelia functionally monoecious.

Where did JS publish on Clivia hybrids? Did he count parent and cross seeds, as Gärtner shows is necessary?

CD has done large experiments on artificially fertilised cowslips. They never resemble oxlips.

Would welcome detailed criticism of natural selection by a careful observer like JS. Most criticism worthless. Expects a great deal from Lyell’s reaction.

Suggests JS do orchid experiment to see if rostellum can be penetrated by pollen.

JS not ready to publish on Primula.

Some of his objections to natural selection are based on belief that plants with separate sexes are less variable than those in which sexes are confluent (as in ferns).

Sends his paper on fern varieties [Edinburgh New Philos. J. 2d ser. 16 (1862): 209–27].

Will soon read paper on Drosera irritability [Edinburgh New Philos. J. 2d ser. 17 (1863): 317–18].

How does CD explain capricious distribution of irritability among plants?

P. scotica’s non-dimorphism is native.

Beginning Laelia experiments shortly.

Criticises style of JS’s fern paper [Edinburgh New Philos. J. 2d ser. 16 (1862): 209–27].

JS’s remark on "the two sexes counteracting variability in the product of the one" is new to CD.

Does the female [fern?] plant always produce female by parthenogenesis?

They seem to work on same subjects; CD has much material on Drosera.

Does not understand JS’s objections to natural selection.

Offers to suggest experiments.

Thanks for Journal of researches and Origin.

Thanks CD for comments on his fern paper [see 3847 and 3853]; has great difficulty in expressing his ideas.

Discusses inheritance and variation.

Asks CD for an account of the experiments he would like JS to perform.

JS should be proud of his paper ["Nature of the fern-spore", Edinburgh New. Philos. J. 2d ser. 16 (1862): 209–27].

CD has just found that JS’s observations on the confluence of two sexes causing variability were independently confirmed by Huxley.

CD has always suspected a fundamental difference between buds and ovules.

Asks for examples of "bud-variation" or "sports".

Asks JS to test germination of pollen on rostellum of Laelia.

Offers JS money for experimental supplies, e.g., netting, to keep insects out of flowers.

Encloses an outline of crossing experiments with Lythraceae, Primula, Pelargonium, and others, which he feels would be valuable.

Note on melastomids.

Sends Primula scotica and P. farinosa.

So far cannot fertilise Gongora atropurpurea although it is similar to Acropera luteola.

Experimenting on intergeneric hybrids to test CD’s view that sterility is not a special endowment.

Scott’s personal history.

Acropera capsule grows.

Plans for experiments CD has suggested on Primula, peloric Antirrhinum, and Verbascum.

Asks about Gärtner’s experiments on maize.

Aware of Anderson-Henry’s failures.

Through kindness of J. H. Balfour and James McNab, enjoys facilities for research. JS is in charge of the propagating department. Balfour almost engaged him to be superintendent of the Madras Horticultural Garden.

CD’s respect for JS’s indomitable work and interesting experiments increases steadily.

His gratitude for the primulas and the astonishing Gongora specimen.

Asks JS’s opinion about crossing a primrose with the pollen of a wild cowslip and of a cultivated polyanthus.

Experiments to cut Laelia stigma from rostellum and then to fertilise rostellum are baffled by "a latent instinctive power". Somehow the pollen-tubes find their way to the style.

Suggests CD study variation in ferns.

Urges JS to publish on orchid pollen-tubes.

Suggests comparing stigmatic tissue of sterile hybrids and fertile parent; he would expect hybrid plant’s cell contents not to be coagulated after 24 hours in spirits of wine.

Suggests JS coat orchid stigmas with plaster of Paris for his work on rostellar germination.

Asks for list of "bud-variation" cases; CD has devoted a chapter to the subject.

Inquiries about I. Anderson-Henry’s observational competence.

Tells JS Acropera capsule should be left to grow.

JS was correct on "bud-variation" in fern frond.

Does not believe Primula structure necessarily related to dioecism, but the difference in fertility of the two forms forced him to admit the possibility.

Sends Acropera capsule for CD to dissect.

Will try to raise Acropera from seed (never done before in Britain) to examine its sexual forms.

Studying primroses, parthenogenesis, and reproduction of some cryptogams.

Received maize varieties from CD.

Thanks JS for the very large Acropera capsule. CD has perhaps made a blunder about the sex of Acropera.

JS was right that successive homomorphic generations of Primula breed true.

JS criticises natural selection as based on an innate "continuously watchful selective principle".

Seeks seed of wild Rocky Mountain maize.

What is CD’s view on origin of maize?

Seeks information on self-sterility of Passiflora and Lobelia.

Weeping habit of trees.

Intended to say bisexual plants presented more established varieties than unisexual, not that they are more variable.

Explains his opinion that homomorphically fertilised Primula will produce only their own form. Is trying homomorphic crosses with different coloured Primula varieties.

Asks to read Asa Gray’s 2d review of Orchids.

Has finally successfully fertilised Gongora, but it was done by unnatural means.

Answers JS’s criticism of natural selection, which he doubts JS understands. CD does not believe in an "innate selective principle".

To understand "utility" JS should read CD on correlation.

Origin of maize: no longer thinks husked form was wild because of Asa Gray’s evidence on its variability.

Has information from Thomas Rivers on weeping habit in trees.

JS’s experiments on coloured primroses.

Encloses bibliographical note on Passiflora.

Thanks for CD’s answers on Passiflora

and Asa Gray review.

Has observed gradation of sterility in Oncidium species.

Has observed rostellar germination and fertilisation in Laelia. The latter was prevented in Bletia by covering the stigma with plaster of Paris.

Gongora atropurpurea capsules are swelling.