Australian Leguminosae problem: of 900 species not ten are common to southwest and southeast. No migration; hence either creation or variation.

Himalayan thistles: graded intermediates between large and small English species, "shakes species to their foundations". Similarity of CD’s and his views on species.

Discusses how best to simulate the light at a particular point on the earth’s surface using coloured glass; considers sunlight as composed of three "principles", varying in proportion according to latitude, which affect germination, lignification, and floriation.

Informs CD which colours of glass accelerate germination, lignification, and floriation; advises CD on obtaining such glass and offers his help in any experiments.

Gives names of German dealers who provide seed of superior quality.

Sends a catalogue of plants [missing] with the close species marked.

Close species in large and small genera.

Artificiality of botanical classification.

Forwards two specimens of beans found on north coast of Norway.

Expresses his general opinion on the relative closeness of species in large and small genera. Warns that the size of a genus is dependent upon the locality and extent of the flora studied, that definitions of close species are not consistent, and that peculiarities of botanical classification will influence any attempt to assess the comparative closeness of species in different genera.

Answers questions presumably sent in CD’s letter [missing] of 5 Oct 1855 after reading RMcA’s work on the geographical distribution of testaceous Mollusca.

Encloses two sets of notes [see 1761 and 1762]. EB believes that as a general rule species do not inter-mix in nature whereas varieties, descendants of a common stock, do. Origin of varieties. Geographically separated species are sometimes obviously distinct and sometimes apparently identical. EB does not believe that species or races of independent origin need necessarily differ. Local distribution of species of black cockatoo contrasts with the widespread white cockatoo. The occurrence of distinct but related species in different regions of a zoological province, preserved because of geographical barriers. Instances of interspecific hybrids and intraspecific sterility. Local varieties of species. Varieties are subdivisions of the main branches of the tree of organisms, dividing irregularly but remaining independent of the twigs from another branch.

Notes on Lyell’s Principles, vol. 2.

EB does not believe in connecting links between genera; there is no tendency to gradation between groups of animals.

Does not believe shortage of food can directly produce any heritable effect on size.

Comments on significance of variations discussed by Lyell. Variation in dentition and coloration.

Behaviour of elephants and monkeys.

When varieties are crossed EB considers that the form of the offspring, whether intermediate or like one or other of the parents, depends upon how nearly related the parents are.

Thinks that in the struggle for existence hybrids, and varieties generally, must be expected to give way to the "beautiful & minute adaptation" of the pure types.

Colours of Indian birds.

Vitality of seeds.

Variation among palms.

Fauna of Malaysia and New Zealand. Ranges of bird species.

[Memorandum originally enclosed with 1760.]

Sends London catalogue of British plants with close species marked.

Charges E. Forbes with fraudulent appropriation of others’ work.

Comments on, and cites possible cases of, CD’s imagined rule that individuals of one or more species in a genus vary in some of those characters by which the species of that genus are distinguished.

Artificiality of orders and genera in botany.

Difficulties in numerical analysis of close species in large and small genera.

HCW has "pretty strong bias towards the view that species are not immutably distinct".

History of the rose in India.

Looks forward to reading what Hooker and Thompson say on species and varieties in their Flora Indica [1855].

Domestication of the turkey in America. The Peruvians had domestic dogs. W. W. Robinson of Assam reports that otters are extensively trained for fishing but cormorants never are. Gives Robinson’s comments on local domestic geese, rabbits, and cats.

EB has skins of jungle fowl from different localities to send.

Observations on shells in India, listing some specimens with particular regard to their locality, elevation, and relationship to other known types.

What does CD think of A. R. Wallace’s paper in the Annals & Magazine of Natural History ["On the law which has regulated the introduction of new species", n.s. 16 (1855): 184–96]? EB considers it good on the whole.

Japanned variety of peacock.

Regional variations in bird species.

EB has little faith in the aboriginal wildness of the Chillingham cattle.

Races of humped cattle of India, China, and Africa.

Indian and Malayan gigantic squirrels, with various races remaining true to their colour, would afford capital data for Wallace, as would the local varieties of certain molluscs. Has Wallace’s lucid collation of facts unsettled CD’s ideas regarding the persistence of species?

Bengal hybrid race of geese is very uniform in colour and as prolific as the European tame goose [see Natural selection, p. 439].

Will see what he can do for CD with regard to domestic pigeons.

Reports success of hybrid cross with Vallota and the failure of another cross.

Sends Madeira specimens, including frogs recently introduced into the island, and flourishing.

Note on cases of representative shells that are not clearly either varieties or species.

Extracts from MS of vol. 4 of HCW’s Cybele Britannica [1847–59] showing the diversity of views on species among botanists.