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 opening-s, that the eye of their enemies cannot penetrate 
within. White eg-gs 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.^ 
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 
* Glbger, Verhand. der Gesells. Natur. Freunde, in Berlin. 
