Discusses the meaning of C. K. Sprengel’s term "dichogamy". Dichogamous plants are functionally monoecious; Primula is functionally dioecious.

Reports Hermann Crüger’s observations of Cattleya and of bees pollinating Catasetum. Crüger will observe Melastomataceae.

Has built a hothouse.

Fears Amsinckia cannot be dimorphic.

Ill health slows his work on Variation.

Fears England and U. S. will drift into war; he and AG must "keep to Science".

Thanks for facts on Incas; regrets he has always avoided the case of man.

Has sent his Linum paper [Collected papers 2: 93–105].

Is it true that Ohio has legislated against marriage of cousins?

Can AG explain the invariable angles in phyllotaxy; are they the consequence of packing in the early bud?

Owen’s comments on heterogeny in the Athenæum [28 Mar 1863] have vexed W. B. Carpenter; CD has replied [Collected papers 2: 78–80].

Hopes AG will observe Gymnadenia; John Scott has been experimenting on its fertilisation.

Gives his observation on pollination of Cypripedium.

CD despairs when men like AG and Lyell consider themselves incapable of judging on change of species by descent.

Is confused over phyllotaxy.

Has been looking at Plantago lanceolata.

AG’s review of Alphonse de Candolle’s paper [Am. J. Sci. 2d ser. 35 (1863): 430–44] is excellent.

Does not AG consider that orchids oppose Oswald Heer’s view that species arise suddenly by monstrosities?

Infers that AG cannot explain the angles of phyllotaxy; has been looking at Carl Nägeli on the subject.

Reports Gaston de Saporta’s belief that natural selection will ultimately triumph in France.

Is working slowly at Variation.

Reports his observations on the imperfect flowers of Viola and Oxalis.

Thanks AG for references about phyllotaxy

and information on marriage laws.

Has been looking for dimorphism in Phlox and Euonymus.

Has observed the irritability of tendrils of Echinocystis with great interest. Was also struck by the rotating movements of the leading shoots, which he proposes to investigate.

Anticipated AG’s attitude on design in orchids. Does he not think that the variations that gave rise to fancy pigeon varieties were accidental?

Has been working hard at Lythrum

and spontaneous movements of tendrils.

Defends Drosera as a "sagacious animal" but does not know whether he will ever publish on it.

Comments on political situation in U. S.

Has not worked for six months due to illness.

Has been looking at climbing plants.

Hermann Crüger’s paper shows that CD was right about Catasetum pollination. Crüger’s account of pollination of Coryanthes "beats everything".

Is slowly writing Lythrum paper [Collected papers 2: 106–31].

Thanks for [Charles?] Wright’s observations on orchids

– could he note what attracts insects to Begonia and Melastoma? H. Crüger, who was going to observe Melastomataceae, has died.

Describes the climbing habits of Bignonia capreolata and Eccremocarpus scaber.

How does AG know the perfect flowers of Voandzeia are quite sterile?

He has a case of dimorphism in holly; asks AG to report on American hollies.

Has finished Climbing plants;

resuming work on Variation.

Sends abstract of John Scott’s paper [see 4332].

Has received review of Herbert Spencer but cannot believe AG wrote it unless he has muddled his brains with metaphysics.

Sends question [missing] for an ornithologist.

Is plodding on at Variation.

Has added to Climbing plants.

Congratulates AG on the "grand news of Richmond".

Still interested in dimorphism and would welcome new cases.

Working on Variation

and correcting proofs of Climbing plants.

Would like seed of AG’s dimorphic Plantago.

Cannot understand how the wind could fertilise reciprocally dimorphic flowers.

Gratified by AG’s praise of "Climbing plants".

Thanks for Specularia seed.

AG’s article on climbing plants [Am. J. Sci. 2d ser. 40 (1865): 273–82] is admirable and complimentary.

Reports Fritz Müller’s observations on climbers.

Experiments on dimorphism with Mitchella and Pulmonaria.

AG’s second article on Climbing plants [Am. J. Sci. 2d ser. 41 (1866): 125–30].

Fritz Müller’s observations on Rubiaceae.

New edition [4th] of Origin.

Thanks for AG’s trouble about new edition of Origin.

Will be printing his new book [Variation] at the end of the year.

[Forwarded by AG, with covering note, to Mr Fields of Ticknor & Fields.]

L. Agassiz’s evidence [for glaciation of America] is very weak.

Thanks AG for arranging for American edition of Variation, but doubts that the book will be successful.

Has found no differences in pollen of Rhamnus so cannot conjecture whether it is dimorphic.

The common oxlip of England is certainly a hybrid between the primrose and the cowslip whereas Primula elatior is a good species.

Reports experiments on the relative vigour of seedlings from cross- and self-fertilised plants.

Thanks AG for his trouble about expression queries; wishes he had thought earlier of having them printed.

Is "plodding on" correcting Variation

and getting "a little amusement" from plant experiments. Oxalis is trimorphic like Lythrum.

Is continuing his experiments on seedling vigour.

Has heard hybrid potatoes can be produced by joining halves of different tubers.

Thanks AG for sending W. M. Canby’s letter on Dionaea. Although already familiar with the facts concerning the secretions, the letter "fires me up to complete and publish on Drosera, Dionæa, etc."

Sends sheets of first volume of Variation.

Transport of seeds in locust dung.

Pangenesis will be called "a mad dream".

Asks that Gray forward a letter to J. T. Rothrock. Variation is selling well. Nearly all chapters were at least partially written before Origin was published.