[211] I may specify, as instances of obscurely-coloured birds building concealed nests, the species belonging to eight Australian genera, described in Gould’s ‘Handbook of the Birds of Australia,’ vol. i. p. 340, 362, 365, 383, 387, 389, 391, 414. [212] Jerdon, ‘Birds of India,’ vol. i. p. 244. [213] On the nidification and colours of these latter species, see Gould’s ‘Handbook,’ &c., vol. i. p. 504, 527. [214] I have consulted, on this subject, Macgillivray’s ‘British Birds,’ and though doubts may be entertained in some cases in regard to the degree of concealment of the nest, and of the degree of conspicuousness of the female, yet the following birds, which all lay their eggs in holes or in domed nests, can hardly be considered, according to the above standard, as conspicuous: Passer, 2 species; Sturnus, of which the female is considerably less brilliant than the male; Cinclus; Motacilla boarula (?); Erithacus (?); Fruticola, 2 sp.; Saxicola; Ruticilla, 2 sp.; Sylvia, 3 sp.; Parus, 3 sp.; Mecistura; Anorthura; Certhia; Sitta; Yunx; Muscicapa, 2 sp.; Hirundo, 3 sp.; and Cypselus. The females of the following 12 birds may be considered as conspicuous according to the same standard, viz., Pastor, Motacilla alba, Parus major and P. cæruleus, Upupa, Picus, 4 sp., Coracias, Alcedo, and Merops. [215] ‘Journal of Travel,’ edited by A. Murray, vol. i. p. 78. [216] See many statements in the ‘Ornithological Biography.’ See, also, some curious observations on the nests of Italian birds by Eugenio Bettoni, in the ‘Atti della Società Italiana,’ vol. xi. 1869, p. 487. [217] See his ‘Monograph of the Trogonidæ,’ first edition. [218] Namely Cyanalcyon. Gould’s ‘Handbook of the Birds of Australia,’ vol. i. p. 133; see, also, p. 130, 136. [219] Every gradation of difference between the sexes may be followed in the parrots of Australia. See Gould’s ‘Handbook,’ &c., vol. ii. p. 14-102. [220] Macgillivray’s ‘British Birds,’ vol. ii. p. 433. Jerdon, ‘Birds of India,’ vol. ii. p. 282. [221] All the following facts are taken from M. Malherbe’s magnificent ‘Monographie des Picidées,’ 1861. [222] Audubon’s ‘Ornithological Biography,’ vol. ii. p. 75; see also the ‘Ibis,’ vol. i. p. 268. [223] Gould’s ‘Handbook of the Birds of Australia,’ vol. ii. p. 109-149. [224] See remarks to this effect in my work on ‘Variation under Domestication,’ vol. ii. chap, xii. [225] The ‘Ibis,’ vol. vi. 1864, p. 122.