Summary

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.

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

Will attempt to provide CD with the information requested as soon as he can.

Gives references to some recent papers and articles which might interest CD.

Is currently reviewing Wallace’s new book [Malay Archipelago].

Summary

There is a possibility of establishment of a Government Museum at Calcutta, with which the Asiatic Society Museum would be merged. EB would like the curatorship but fears other possible applicants. Asks CD to represent him to W. H. Sykes.

Discusses the ancients’ awareness of various cats as deduced from the etymology of their names.

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

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

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.]