168 



EGGS OF BIRDS. 



The eggs are also white among- some species, which, like the domestic 

 swallow, certain passeres, the troglodytes, &c, construct their nests with 

 such narrow openings, that the eye of their enemies cannot penetrate 

 within. White eggs are also found with birds that quit them only 

 during the night, or at least very late during the day, such as the owls 

 and falcons. Lastly, this colour is found among birds which lay only 

 one or two eggs, and sit immediately after, like the pigeons, the 

 boobies, and the petrels. As to the bright green or blue colour, it is 

 found to belong to many species which make their nests in hollows, 

 like the starling, the bullfinch, the fly-catcher, &c. In the second 

 place, this colour is common to the egg of birds, the nests of which are 

 constructed of green moss, or placed at least in the midst of grass, but 

 always well concealed; such, for example, as the tomtit, linnet, &c. 

 Lastly, green eggs are met with among many strong birds able to 

 defend themselves against plunderers, like the herons. A light green 

 colour, verging toward a yellowish tint, is found among the eggs of the 

 many gallinacea which lay among the grass, without making a finished 

 nest, which soon disappears beneath the quantity of eggs ; like the 

 hoopoe, the perdrix cinereus, the pheasant. The same colour is also 

 remarked among several of the palmipedes, which quit their eggs when 

 they lay them, but which are attentive in watching them, as the swans, 

 the geese, the ducks, the divers, &c. The eggs of certain great birds 

 which make their nests in the open air, but are well able to defend 

 themselves, are a dirty white, as may be observed among the vultures, 

 eagles, storks. Among the eggs of a mixed colour, they are to be dis- 

 tinguished which have a white ground, and those of which the ground 

 differs from white. The eggs with a white ground are those of the 

 European oriole, the long-tailed tit, the cole-tit, the nut-hatch, the 

 creeper, and the common swallow. Most of the eggs with a white 

 ground are concealed in well-covered nests. The eggs of a mixed 

 colour, and of which the ground is not white, at least of a pure white, 

 are those of the lark, the grasshopper-lark, the yellow-hammer, the 

 wagtail, &c. ; then the crows, the jays, the thrushes, the quails, &c, 

 with most of the singing birds, the colour of the interior of whose nest 

 harmonizes with that of the eggs. 1 



With all due deference, however, to M. Glbger, I would remark that 

 the theory appears to me much more beautiful and ingenious than 

 true; for I could enumerate more instances in which the principle fails 

 than holds good. Glbger's instances, also, are far from accurate ; for 



1 Gloger, Verhand. der Gesells. Natur. Freunde, in Berlin. 



