[4]Some egrets, such as the rock-egrets (_Demiegretta_) of eastern tropical coasts, are normally grey, but may be white, and this whiteness may be confined in individuals to the young or adult states. [5]After years of observation of these Indian geese, Finn is convinced they are now, at all events, pure Chinese; it is possible that they really were hybrids in Blyth’s time, but that fresh importations of geese from China, such as still occur, may have ultimately swamped the blood of the common goose. The fertility of the hybrid geese was, however, known to such early writers as Pallas and Linnæus. Darwin himself, at a later date, bred five young from a pair of such hybrids (_Nature_, Jan. 1, 1880, p. 207). [6]In this chapter we use the word Neo-Darwinism in its usually-accepted sense, _i.e._ as a name for that which should be called Wallaceism, for the doctrine of the all-sufficiency of natural selection. [7]_Animal Colouration_, p. 125. A book full of valuable facts and ideas on this most interesting subject. [8]Even these eggs, closely though they resemble in colouring the shingle, etc., on which they are laid, are discovered and eaten by gulls, as Mr A. J. R. Roberts points out in _The Bird Book_. [9]_Journal of the Bombay Natural History Society_, Vol xv. (1903-4), p. 454. [10]Hutton and Drummond record other examples of this in the valuable work entitled _The Animals of New Zealand_. INDEX