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.]

Summary

Gives extract from a letter from Capt. R. Tickell: rabbits are not bred by the Burmese; common European and Chinese geese are bred but have probably only recently been introduced.

EB gives references to works illustrating the dog-like instinct of N. American wolves.

Discusses reason and instinct; ascribes both to man and animals. Comments on various instincts, e. g. homing, migratory, parental, constructive, and defensive. Reasoning in animals; cattle learning to overcome fear of passing trains.

Hybrid sterility as an indication of distinct species. Interbreeding as an indication of common parentage.

Enlarges upon details given by J. C. Prichard [in The natural history of man (1843)].

Adaptation of the two-humped camel to cold climates. Camel hybrids.

Doubts that domestic fowl or fancy pigeons have ever reverted to the wild.

Feral horses and cattle of S. America.

Believes the "creole pullets" to be a case of inaccurate description.

Variations in skulls between species of wild boar.

Pigs are so prolific that the species might be expected to cross.

Milk production of cows and goats.

Sheep and goats of lower Bengal.

Indian breeds of horses.

Variation in Asiatic elephants.

Spread of American tropical and subtropical plants in the East.

EB distinguishes between races and artificially-produced breeds.

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

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

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

Corrects some facts and gives further information on some points for the 2d ed. of Variation.

Specific distinctions among animals.

Cercopithecus of Africa contrasted with the Cebus of South America.

Notes on domestic fowls and their ancestors.

Slow growth of wild animals compared with domestic varieties.

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.]