Summary

Sexual differences in bird species and seasonal variation in plumage.

Summary

Comments on the ease with which different species of Felis can be tamed.

Asian species of wild cattle.

Variation in colour of jackals.

Discusses the difficulties of differentiating between varieties and species. EB recommends Herman Schlegel’s definition of species [in Essay on the physiognomy of serpents, trans. T. S. Traill (1843)]. Problems of defining species of wolves and squirrels. Pigeons and doves afford an illustration of "clusters of species, varieties, or races". Various pigeons have local species in different parts of India and Burma, some of which interbreed where their ranges cross; as do the local species of Coracias [see Natural selection, p. 259].

[CD’s notes are an abstract of this memorandum.]

Summary

Detailed notes on secondary sexual differences in various species of birds and mammals.

Summary

Encloses memorandum on Origin [1866]

discussing mimicry in mammals and birds,

abnormal habits shown by birds,

behaviour of cuckoos,

and analogies existing between mammals of the same geographical region.

Speculates on possible lines of development linking groups of mammals.

[CD’s notes on the verso of the letter are for his reply.]

Summary

Gives CD reference to case of the saiga, an antelope, fearless of man.

Reports observations by New Zealander who has seen heaps of pebbles presumably voided by Dinornis.

Summary

Origin of domestic varieties. EB ascribes "abnormal" variations to man’s propagation of casual monstrosities; believes "normal" variations, e.g. European races of cattle, are a consequence of man’s selecting the choicest specimens. Gives examples of "abnormal" variations; they give rise to features that have no counterpart among possible wild progenitors. Divides domestic animals into those whose origin is known and those whose origin is unknown. Considers that the wild progenitors of nearly all domestic birds are known. Fowls and pigeons show many varieties but if propagated abnormalities are ignored each group can be seen to be variations of a single species, the ancestors of which can be recognised without difficulty. Discusses varieties and ancestry of the domestic fowl. Variation in the wild; the ruff shows exceptional variability; other species of birds show variability in size of individuals. Remarks that markings sometimes vary on different sides of the same animal. Comments on the want of regularity in leaf and petal patterns of some plants. Discusses domestic varieties of reindeer and camels. Origin of humped cattle. Reports the rapid spread of a snail in lower Bengal that was introduced as a single pair five or six years previously.

[CD’s notes are an abstract of part of this memorandum. Memorandum originally enclosed with 1760.]

Summary

Discusses sexual and seasonal differences in the plumage of birds and coats of mammals.

Remarks upon variations in the form of the canine tooth between the sexes in mammalian groups.

Plumage of allied species of plover.

Asks CD’s help with work on unimproved domestic animals.

Summary

Discusses apes and their relationships to each other. Writes particularly of the gibbon, its structure and well-developed legs giving it the ability to walk without using its hands.

Summary

Has found no difference between male and female rhesus monkeys at the Zoological Gardens in amount of facial hairiness. Observations on other monkeys.

Summary

Believes the goldfish originates from a wild, gold variety of Chinese carp.

Gallinaceous birds.

Crested turkeys.

EB divides the gallinaceous birds into five families on anatomical distinctions.

Wild dog species of India and Asia; ranges of some species, specific identity of others.

The fauna of the Seychelles.

Breeding of fowls in India and Africa.

Occurrence of turkeys in Africa.

Refers to some of his own papers giving fuller details of points raised previously.

Summary

Sends a skeleton of a Bengal jungle cock.

Has never heard of trained otters breeding in captivity.

Introduced domestic rabbits are confined to the ports of India.

Canaries and other tame finches and thrushes brought into India do not breed well.

Origin of the domestic canary. Tendency of domesticated birds to produce "top-knot" varieties.

The tame geese of lower Bengal are hybrids; those of upper Bengal are said to be pure Anser cygnoides.

Wild Anser cinereus occur in flocks in the cold season.

Discusses at length different breeds of domestic cats and possible wild progenitors. Wild and domestic cats occasionally interbreed. The Angora variety breeds freely with the common Bengal cat and all stages of intermediates can be found.

Believes pigeons have been bred in India since remote antiquity.

Discusses whether mankind is divided into races or distinct species.

[CD’s notes are an abstract of this letter.]

Summary

Indigenous domestic animals of the New World.

Relationship of Newfoundland and Esquimo dogs to the wolf. Dogs like the Esquimo occur in Tibet and Siberia. Indian pariah dogs and jackals occasionally interbreed.

Describes domestic cats of India; reports cases of their interbreeding with wild cats. Wild cats are tamed for hunting.

Races of silkworm in India are crossed [see 1690].

Domesticated plants, fish, and birds of India.

Comments on local races and species of crows; it is impossible to trace a line of demarcation between races and species.

Variation in the ability of hybrids to propagate.

Indian cattle breeds; differences between Bos indicus and Bos taurus.

Is not satisfied that aboriginally wild species of horse and ass exist.

Believes all fancy breeds of pigeon originated in the East. Wild ancestors of pigeons, ducks, geese, and fowls. Interbreeding of wild species of pheasant.

[CD’s notes are an abstract of this letter.]

Summary

Encloses "notes for Mr. D" [see 1818] and a memorandum on the wild cattle of southern India [see 1819].

Breeds of silky fowl of China and Malaya. Black-skinned fowl.

Doubts any breed of canary has siskin blood; all remain true to their type.

Wild canary and finch hybrids.

Hybrids between one- and two-humped camels.

Does not regard zebra markings on asses as an indication of interbreeding but as one of the many instances of markings in the young which more or less disappear in the adult.

Crossing of Coracias species at the edges of their ranges.

Regional variations and intergrading between species of pigeons.

Regards the differences in Treron as specific [see Natural selection, p. 115 n. 1].

Gives other instances of representative species or races differing only in certain details of colouring.

Summary

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.]