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].

Studying self-sterility, particularly in Oncidium, where abortion occurs consistently but stigma functions normally. His hybrid orchid crosses show sterility occurs capriciously. Thus it is not a "special endowment".

Disputes Asa Gray’s and Hermann Crüger’s view of rostellar germination.

Doubts absolute sterility of Catasetum.

Disappointed by results with homomorphic cowslips.

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 JS for orchid paper [Trans. Bot. Soc. Edinburgh 7 (1863): 543–50]. JS presents excellent new facts on sterility of orchids.

His argument that coloured primroses are not hybrids is good, as is idea of discovering primrose parentage by breeding for colours.

Sends Passiflora paper [see 4485].

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

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 expression and colour of beard and hair in natives of India.

Thanks for Cross and self-fertilisation.

His work on poppy varieties confirms increased vigour with crossing.

JS is carrying out opium poppy experiments CD suggested. He is busy with opium duties. Observing many fields of poppies, day and night, JS finds them remarkably free of insects. Believes they are wind-pollinated and that varieties have prepotent pollen since he has shown they do not cross naturally.

Plans to send a paper on Cyclosis to Linnean Society.

Comments on various species of Lagerstroemia.

In the series of opium poppy intercrosses made at CD’s suggestion, JS has learned that the reason they failed to intercross was the absence of insects at the period of their flowering.

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.

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.

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.