[157] 'A Tour in Sutherlandshire,' vol. i. 1849, p. 185.

[158] 'Acclimatization of Parrots,' by C. Buxton, M.P. 'Annals and Mag. of Nat. Hist.' Nov. 1868, p. 381.

[159] 'The Zoologist,' 1847-1848, p. 1602.

[160] Hewitt on wild ducks, 'Journal of Horticulture,' Jan. 13, 1863, p. 39. Audubon on the wild turkey, 'Ornith. Biography,'

vol. i. p. 14. On the mocking thrush, ibid. vol. i. p. 110.

[161] The 'Ibis,' vol. ii. 1860, p. 344.

[162] On the ornamented nests of humming-birds, Gould, 'Introduction to the Trochilidae,' 1861, p. 19. On the bower-birds, Gould, 'Handbook to the Birds of Australia,' 1865, vol. i. p. 444-461. Mr. Ramsay in the 'Ibis,' 1867, p. 456.

[163] 'Hist. of British Birds,' vol. ii. p. 92.

[164] 'Zoologist,' 1853-1854, p. 3946.

[165] Waterton, 'Essays on Nat. Hist.' 2nd series, p. 42, 117.

For the following statements, see on the wigeon, Loudon's 'Mag.

of Nat. Hist.' vol. ix. p. 616; L. Lloyd, 'Scandinavian Adventures,' vol. i. 1854, p. 452; Dixon, 'Ornamental and Domestic Poultry,' p. 137; Hewitt, in 'Journal of Horticulture,' Jan. 13, 1863, p. 40; Bechstein. 'Stubenvogel,'

1840, s. 230.

[166] Audubon, 'Ornitholog. Biography,' vol. i. p. 191, 349; vol. ii. p. 42, 275; vol. iii. p. 2.

[167] 'Rare and Prize Poultry,' 1854, p. 27.

[168] 'The Variation of Animals and Plants under Domestication,' vol. ii. p. 103.

[169] Boitard and Corbie, 'Les Pigeons,' 1824, p. 12. Prosper Lucas ('Traite de l'Hered. Nat.' tom. ii. 1850, p. 296) has himself observed nearly similar facts with pigeons.

[170] 'Die Taubenzucht,' 1824, s. 86.

[171] 'Ornithological Biography,' vol. i. p. 13.

[172] 'Proc. Zool. Soc.' 1835, p. 54. The j.a.panned peac.o.c.k is considered by Mr. Sclater as a distinct species, and has been named _Pavo nigripennis_.

[173] Rudolphi, 'Beytrage zur Anthropologie,' 1812, s. 184.

[174] 'Die Darwin'sche Theorie, und ihre Stellung zu Moral und Religion,' 1869, s. 59.

[175] In regard to peafowl, see Sir R. Heron, 'Proc. Zoolog.

Soc.' 1835, p. 54, and the Rev. E. S. Dixon, 'Ornamental Poultry,' 1848, p. 8. For the turkey, Audubon, ibid. p. 4. For the capercailzie, Lloyd, 'Game Birds of Sweden,' 1867, p. 23.

[176] Mr. Hewitt, quoted in 'Tegetmeier's Poultry Book,' 1866, p. 165.

[177] Quoted in Lloyd's 'Game Birds of Sweden,' p. 345.

[178] According to Dr. Blasius ('Ibis,' vol. ii. 1860, p. 297), there are 425 indubitable species of birds which breed in Europe, besides 60 forms, which are frequently regarded as distinct species. Of the latter, Blasius thinks that only ten are really doubtful, and that the other fifty ought to be united with their nearest allies; but this shews that there must be a considerable amount of variation with some of our European birds. It is also an unsettled point with naturalists, whether several North American birds ought to be ranked as specifically distinct from the corresponding European species.

[179] 'Origin of Species,' fifth edit. 1869, p. 104. I had always perceived, that rare and strongly-marked deviations of structure, deserving to be called monstrosities, could seldom be preserved through natural selection, and that the preservation of even highly-beneficial variations would depend to a certain extent on chance. I had also fully appreciated the importance of mere individual differences, and this led me to insist so strongly on the importance of that unconscious form of selection by man, which follows from the preservation of the most valued individuals of each breed, without any intention on his part to modify the characters of the breed. But until I read an able article in the 'North British Review' (March, 1867, p. 289, _et seq._), which has been of more use to me than any other Review, I did not see how great the chances were against the preservation of variations, whether slight or strongly p.r.o.nounced, occurring only in single individuals.

[180] 'Introduct. to the Trochilidae,' p. 102.

[181] Gould, 'Handbook of Birds of Australia,' vol. ii. p. 32 and 68.

[182] Audubon, 'Ornitholog. Biography,' 1838, vol. iv. p. 389.

[183] Jerdon, 'Birds of India,' vol. i. p. 108; and Mr. Blyth, in 'Land and Water,' 1868, p. 381.

[184] Graba, 'Tagebuch, Reise nach Faro,' 1830, s. 51-54.

Macgillivray, 'Hist. British Birds,' vol. iii. p. 745. 'Ibis,'

vol. v. 1863, p. 469.

[185] Graba, ibid. s. 54. Macgillivray, ibid. vol. v. p. 327.

[186] 'Variation of Animals and Plants under Domestication.'

vol. ii. p. 92.

[187] On these points see also 'Variation of Animals and Plants under Domestication,' vol. i. p. 253; vol. ii. p. 73, 75.

[188] See, for instance, on the irides of a Podica and Gallicrex in 'Ibis,' vol. ii. 1860, p. 206; and vol. v. 1863, p. 426.

[189] See also Jerdon, 'Birds of India,' vol. i. p. 243-245.

[190] 'Zoology of the Voyage of H.M.S. Beagle,' 1841, p. 6.

[191] Bechstein, 'Naturgeschichte Deutschlands,' B. iv. 1795, s. 31, on a sub-variety of the Monck pigeon.

[192] This woodcut has been engraved from a beautiful drawing, most kindly made for me by Mr. Trimen; see also his description of the wonderful amount of variation in the coloration and shape of the wings of this b.u.t.terfly, in his, 'Rhopalocera Africae Australis,' p. 186. See also an interesting paper by the Rev. H. H. Higgins, on the origin of the ocelli in the Lepidoptera in the 'Quarterly Journal of Science,' July, 1868, p. 325.

[193] Jerdon, 'Birds of India,' vol. iii. p. 517.

[194] 'Variation of Animals and Plants under Domestication,'

vol. i. p. 254.

[195] When the Argus pheasant displays his wing-feathers like a great fan, those nearest to the body stand more upright than the outer ones, so that the shading of the ball-and-socket ocelli ought to be slightly different on the different feathers, in order to bring out their full effect, relatively to the incidence of the light. Mr. T. W. Wood, who has the experienced eye of an artist, a.s.serts ('Field,' Newspaper, May 28, 1870, p. 457) that this is the case; but after carefully examining two mounted specimens (the proper feathers from one having been given to me by Mr. Gould for more accurate comparison) I cannot perceive that this acme of perfection in the shading has been attained; nor can others to whom I have shewn these feathers recognise the fact.

[196] 'The Reign of Law,' 1867, p. 247.

[197] 'Introduction to the Trochilidae,' 1861, p. 110.

[198] Fourth edition, 1866, p. 241.

[199] 'Westminster Review,' July, 1867. 'Journal of Travel,'

vol. i. 1868, p. 73.

[200] Temminck says that the tail of the female _Phasia.n.u.s Smmerringii_ is only six inches long, 'Planches coloriees,' vol. v. 1838, p. 487 and 488: the measurements above given were made for me by Mr. Sclater. For the common pheasant, see Macgillivray, 'Hist. Brit. Birds,' vol. i. p.

118-121.

[201] Dr. Chapuis, 'Le Pigeon Voyageur Belge,' 1865, p. 87.