Page:The Zoologist, 4th series, vol 2 (1898).djvu/433

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ASSIMILATIVE COLOURATION.
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haggard and miserable got quite plump and fresh; some of them ate about thirty at a meal, and we now saw each other with clean faces, for we used the eggs as soap; while a most remarkable thing was that everyone had fair skins and light hair, dark faces and hair being quite changed, black hair turning brown or red, and fairer people quite flaxen. As for myself, my complexion was pink and white, like a girl's" (this after four months' constant exposure to the weather), "with white eyebrows, yellow hair, &c."

The survivors were rescued on Jan. 21st, 1876, and the same lady subsequently writes:—"Charlie looks well and firm now, his hair had got quite flaxen, which did not suit him at all, but now it has nearly recovered its original colour."[1] Here, presumably, the colouring factor is considered as the constant diet of Penguins' eggs. As Darwin has observed: "There can, however, be little doubt about many slight changes, such as size from the amount of food, colour from the nature of the food."[2] Climatic conditions are not altogether inoperative, and an extreme case is recorded by Andersson in the Ovambo country, South-west Africa. In describing the bitterly cold nights experienced in the month of June, he states that one of his men, Timbo, a native of Portuguese East Africa, suffered much from the low temperature, and one morning the members of the expedition were amazed at finding "his dark shiny skin suddenly changed into a pale ashy grey."[3]

The view of a direct action caused by a constant food on animal colouration has frequently been remarked. Mr. Harvie Brown thought that the Sand Martin might derive its black or dark-coloured plumage in North Russia by constant feeding on Mosquitos.[4] Most natives of Brazil take pleasure in intercourse with animals. They are in the habit of attaching Monkeys and Parrots to themselves, and by feeding the latter on fish they produce red and yellow feathers when the plumage is green.[5] The Bullfinch is well known to turn black when fed on hempseeds, and the Canary to become red when fed on cayenne pepper.[6] According to Mr. Harting, "Bullfinches are not the

  1. 'Nature,' vol. xiv. p. 527 (quoted from 'Blackwood's Magazine').
  2. 'Origin of Species,' 6th edition, p. 6.
  3. 'Lake Ngami,' p. 210.
  4. 'Zoologist,' p. 5162.
  5. Oscar Peschel, 'The Races of Man,' p. 423.
  6. Romanes, 'Darwin, and after Darwin,' vol. ii. p. 218.