[2] ‘An Essay on Animal Reproduction,’ Eng. translat., 1769, p. 79.

[3] Carpenter’s ‘Principles of Comp. Physiology,’ 1854, p. 479.

[4] Charlesworth’s ‘Mag. of Nat. Hist.,’ vol. i. 1837, p. 145.

[5] Paget, ‘Lectures on Surgical Pathology,’ vol. i. p. 239.

[6] Quoted by Carpenter, ‘Comp. Phys.,’ p. 479.

[7] Prof. Marey’s discussion on the power of co-adaptation in all parts of the organisation is excellent. ‘La Machine Animale,’ 1873, chap. ix. See also Paget, ‘Lectures,’ etc., p. 257.

[8] These cases are given by Blumenbach in his ‘Essay on Generation,’ pp. 52, 54.

[9] ‘Cellular Pathology,’ trans. by Dr. Chance, 1860, pp. 27, 441.

[10] Paget, ‘Lectures on Pathology,’ vol. i. 1853, p. 357.

[11] Paget, ibid., p. 150.

[12] ‘Die Blutvertheilung, etc. der Organe,’ 1871, as quoted by Jaeger, ‘In Sachen Darwin’s,’ 1874, p. 48. See also H. Spencer ‘The Principles of Biology,’ vol. ii. 1866, chap. 3-5.

[13] ‘Lectures on Pathology,’ 1853, vol. i. p. 71.

[14] ‘Comptes Rendus,’ Sept. 26th, 1864, p. 539.

[15] H. Spencer, ‘The Principles of Biology,’ vol. ii. p. 243.

[16] Ibid., vol. ii. p. 269. Sachs, ‘Text-book of Botany,’ 1875, p. 734.

[17] Ibid., vol. ii. p. 273.

[18] Paget, ‘Lectures on Pathology,’ vol. ii. p. 209.

[19] Müller’s ‘Phys.,’ Eng. translat., pp. 54, 791. Prof. Reed has given (‘Physiological and Anat. Researches,’ p. 10) a curious account of the atrophy of the limbs of rabbits after the destruction of the nerve.

[20] Quoted by Lecoq, in ‘Géograph. Bot.,’ tom. i. 1854, p. 182.

[21] ‘Das Abändern der Vögel,’ 1833, s. 74.

[22] Nathusius, ‘Die Racen des Schweines,’ 1860, s. 53, 57; ‘Vorstudien . . . Schweineschädel,’ 1864, s. 103, 130, 133. Prof. Lucae supports and extends the conclusions of Von Nathusius: ‘Der Schädel des Maskenschweines,’ 1870.

[23] ‘Journal of Agriculture of Highland Soc.,’ July 1860, p. 321.

[24] ‘Landwirth. Wochenblatt,’ No. 10.

[25] ‘Lectures on Surgical Pathology,’ 1853, vol. i. p. 27.

[26] Andersson, ‘Travels in South Africa,’ p. 318. For analogous cases in South America see Aug. St.-Hilaire ‘Voyage dans la Province de Goyaz,’ tom. i. p. 71.

[27] Brickell’s ‘Nat. Hist. of North Carolina,’ 1739, p. 53.

[28] Livingstone, quoted by Youatt on Sheep, p. 142. Hodgson in ‘Journal of Asiatic Soc. of Bengal,’ vol. xvi. 1847, p. 1006, etc. etc. On the other hand, Dr. Wilckens argues strongly against the belief that the drooping of the ears is the result of disuse: ‘Jahrbuch der deutschen Viehzucht,’ 1866.

[29] ‘Naturalist’s Library,’ Dogs, vol. ii. 1840, p. 104.

[30] ‘De l’Espèce,’ tom. i. 1859, p. 367.

[31] ‘Ceylon,’ by Sir J. E. Tennent, 1859, vol. ii. p. 531.

[32] For the foregoing statements, see Hunter’s ‘Essays and Observations,’ 1861, vol. ii. p. 329; Dr. Edmondston, as quoted in Macgillivray’s ‘British Birds,’ vol. v. p. 550: Menetries, as quoted in Bronn’s ‘Geschichte der Natur,’ B. ii. s. 110.

[33] These statements on the intestines are taken from Isidore Geoffroy Saint-Hilaire, ‘Hist. Nat. Gén.,’ tom. iii. pp. 427, 441.

[34] Gilbert White, ‘Nat. Hist. Selborne,’ 1825, vol. ii. p. 121.

[35] Burdach, ‘Traité de Phys.,’ tom. ii. p. 267, as quoted by Dr. P. Lucas, ‘L’Héréd. Nat.,’ tom. i. p. 388.

[36] This and several other cases are given by Colin, ‘Physiologie Comp. des Animaux Dom.,’ 1854, tom. i. p. 426.

[37] M. Michely de Cayenne, in ‘Bull. Soc. d’Acclimat.,’ tom. viii. 1861, p. 563.

[38] Quatrefages, ‘Unité de l’Espèce Humaine,’ 1861, p. 79.

[39] ‘The American Naturalist,’ April 1874, p. 237.

[40] ‘Flora,’ 1835, B. ii. p. 504.

[41] Alph. de Candolle, ‘Géograph. Bot.,’ tom. ii. p. 1078.

[42] Royle, ‘Illustrations of the Botany of the Himalaya,’ p. 19.

[43] ‘Gardener’s Chronicle,’ 1850, pp. 204, 219.

[44] Rev. R. Everest, ‘Journal As. Soc. of Bengal,’ vol. iii. p. 19.

[45] Youatt on Sheep, 1838, p. 491.

[46] Royle, ‘Prod. Resources of India,’ p. 153.

[47] Tegetmeier, ‘Poultry Book,’ 1866, p. 102.

[48] Dr. R. Paterson, in a paper communicated to Bot. Soc. of Canada quoted in the ‘Reader,’ 1863, Nov. 13th.

[49] See remarks by Editor in ‘Gardener’s Chronicle,’ 1848, p. 5.

[50] ‘Gardener’s Chronicle,’ 1860, p. 938. Remarks by Editor and quotation from Decaisne.

[51] J. de Jonghe, of Brussels, in ‘Gardener’s Chronicle,’ 1857, p. 612.

[52] Ch. Martius, ‘Voyage Bot. Côtes Sept. de la Norvège,’ p. 26.

[53] ‘Journal de l’Acad. Hort. de Gand,’ quoted in ‘Gardener’s Chronicle,’ 1859, p. 7.

[54] ‘Gardener’s Chronicle,’ 1851, p. 396.

[55] Ibid., 1862, p. 235.

[56] On the authority of Labat, quoted in ‘Gardener’s Chronicle,’ 1862, p. 235.

[57] MM. Edwards and Colin, ‘Annal. des Sc. Nat.,’ 2nd series, Bot., tom. v. p. 22.

[58] ‘Géograph. Bot.,’ p. 337.

[59] ‘Swedish Acts,’ Eng. translat., 1739-40, vol. i. Kalm, in his ‘Travels,’ vol. ii. p. 166, gives an analogous case with cotton-plants raised in New Jersey from Carolina seed.

[60] De Candolle, ‘Géograph. Bot.,’ p. 339.

[61] ‘Gardener’s Chronicle,’ 1862, p. 235.

[62] Gallesio, ‘Teoria della Riproduzione Veg.,’ 1816, p. 125; and ‘Traité du Citrus,’ 1811, p. 359.

[63] ‘Essai sur l’Hist. des Orangers,’ 1813, p. 20, etc.

[64] Alph. de Candolle, ‘Géograph. Bot.,’ p. 882.

[65] ‘Ch. Darwin’s Lehre von der Entstehung,’ etc., 1862, s. 87.

[66] Decaisne, quoted in ‘Gardener’s Chronicle,’ 1865, p. 271.

[67] For the magnolia, see Loudon’s ‘Gardener’s Mag.,’ vol. xiii. 1837, p. 21. For camellias and roses, see ‘Gardener’s Chronicle,’ 1860, p. 384. For the yew, ‘Journal of Hort.,’ March 3rd, 1863, p. 174. For sweet potatoes, see Col. von Siebold, in ‘Gardener’s Chronicle,’ 1855, p. 822.

[68] The Editor, ‘Gardener’s Chronicle,’ 1861, p. 239.

[69] Loudon’s ‘Gardener’s Mag.,’ vol. xii. 1836, p. 378.

[70] ‘Gardener’s Chronicle,’ 1865, p. 699. Mr. G. Maw gives (‘Gardener’s Chronicle,’ 1870, p. 895) a number of striking cases; he brought home from southern Spain and northern Africa several plants, which he cultivated in England alongside specimens from northern districts; and he found a great difference not only in their hardiness during the winter, but in the behaviour of some of them during the summer.

[71] ‘Arboretum et Fruticetum,’ vol. iii. p. 1376.

[72] Mr. Robson, in ‘Journal of Horticulture,’ 1861, p. 23.

[73] Dr. Bonavia, ‘Report of the Agri.-Hort. Soc. of Oudh,’ 1866.

[74] ‘Cottage Gardener,’ 1860, April 24th, p. 57.

[75] ‘Gardener’s Chronicle,’ 1841, p. 291.

[76] Mr. Beaton, in ‘Cottage Gardener,’ March 20th, 1860, p. 377. Queen Mab will also stand stove heat. See ‘Gardener’s Chronicle,’ 1845, p. 226.

[77] ‘Gardener’s Chronicle,’ 1841, p. 439.

[78] Quoted by Asa Gray, in ‘Am. Journ. of Sc.,’ 2nd series, Jan. 1865, p. 106.

[79] For China, see ‘Mémoire sur les Chinois,’ tom. xi. 1786, p. 60. Columella is quoted by Carlier, in ‘Journal de Physique,’ tom. xxiv. 1784.

[80] Messrs. Hardy and Son, in ‘Gardener’s Chronicle,’ 1856, p. 589.

[81] Isid. Geoffroy Saint-Hilaire, ‘Hist. Nat. des Anomalies,’ 1836, tom. ii. pp. 210, 223, 224, 395; ‘Philosoph. Transact.,’ 1775, p. 313.

[82] Pallas, quoted by Youatt on Sheep, p. 25.

[83] Youatt on Cattle, 1834, p. 174.

[84] ‘Encyclop. Méthod.,’ 1820, p. 483: see p. 500, on the Indian zebu casting its horns. Similar cases in European cattle were given in the third chapter.

[85] Pallas, ‘Travels,’ Eng. Translat., vol. i. p. 243.

[86] Mr. Beaton, in ‘Journal of Horticulture,’ May 21st, 1861, p. 133.

[87] Lecoq, ‘De la Fécondation,’ 1862, p. 233.

[88] ‘Annales du Muséum,’ tom. vi. p. 319.

[89] I suggested in ‘Nature’ (vol. 8 pp. 432, 505) that with organisms subjected to unfavourable conditions all the parts would tend towards reduction, and that under such circumstances any part which was not kept up to its standard size by natural selection would, owing to intercrossing, slowly but steadily decrease. In three subsequent communications to ‘Nature’ (March 12, April 9, and July 2, 1874), Mr. Romanes gives his improved view.