On the Production of Colour in Birds Eggs. 57 



straked, speckled and spotted.'' It is then not difticult to 

 understand that surrounding objects of very different 

 appearance, but of unequally coloured surface, might as 

 readily produce spots and speckles on bird's eggs, as on the 

 skins of mammals. 



In the case of the honey-eaters, we may venture a surmise 

 as to what the parti-coloured objects are which produce the 

 spotted eggs. The eggs of these birds are of various shades 

 of ground colour, white, buff* salmon, flesh-coloured, with 

 small dots or flecks of purple, chestnut, reddish-brown, or 

 even black. The birds, as their name denotes, may be seen 

 busily extracting the honey from the flowers by means of 

 their long tongues. Familiarity with pale and warm-tinted 

 flowers and with the dotted orange, red, purple, or black 

 anthers, may possibly account for the coloration of this 

 type of egg. 



Many birds which nest in trees or bushes have eggs 

 vv^hich are of a pale or darker green ground hue, speckled or 

 splashed over with olive or brown, reminding one of the 

 different shades of the surrounding foliage, and, moreover, 

 difiicult to see from a distance through a bower of leaves. 

 Such are the eggs of the crows, magpies, and crow-shrikes, 

 the species of grauculus, the English black-birds, and the 

 Australian mountain thrush and robins. In this case both 

 origin and use of the colour are apparent. 



Eggs with irregular streaky lines of bizarre appearance 

 are found in a few families. In England, the yellow-hammers 

 and buntings are good examples. In Australia, we have the 

 Pomatostovii. The eggs of the latter are about an inch long 

 and three-quarters of an inch at the widest, olive-brown, 

 with all kinds of hieroglyphic pencillings in black. Both 

 families line their nests with hair, and the eggs are protected 

 by their resemblance to the lining of the nest. Gould simi- 

 larly remarks, in speaking of the Victorian lyre-bird, ''the 

 colour resembles, in fact so closely, that of the feathers with 

 which the nest is lined, that it is not easy to detect the egg.'* 



Eggs of a pale bluish or greenish uniform tint are common. 

 Such neutral tints are found in the grebes, cormorants, 

 swans, ducks, and geese, the mangrove bitterns, the glossy 

 ibis ; and attaining to the deepest and loveliest shade in the 

 herons. Just as the hue of the eggs of the pheasants, &c., 

 may have been suggested by that of mother earth ever 

 before their eyes, so these tints of the water birds' eggs may 

 have arisen from the contemplation of vast sheets of water. 



