NESTS AND EGGS. 
richly marked, produces a pale-coloured egg. The colour of 
eggs has, therefore, no connection with the plumage of the bird. 
Whatever may be the explanation, it is obvious enough, 
of course, that the pigment is animal matter; but it would 
appear, from the investigations of M. Geofir oy de Saint-Hilaire 
and other scientific men, that the egg, immediately before it is 
deposited, is white. The colour may also be scraped off par- 
tially immediately after it is laid ; and when “ blown ” for 
preservation, that is, when deprived of its albuminous con- 
tents, the colour fades when exposed to the sun, as any 
one may satisfy himself by glancing at the collection of 
birds’ eggs in the British Museum, where the efforts of 
the obliging curator have altogether failed in devising means 
for preserving their markings ; so that the rich ruddy blotches 
of the peregrine and other falcons’ eggs, which are the most 
striking in their markings, as may be seen on our plate, are 
there reduced to a sober grey. The vividness of the colours 
also appears to depend on the bird being in a healthy state. 
Many variations are found in the colour of eggs of the same 
species, and the eggs of birds disturbed in the act of laying 
are always deficient in their markings; the animal economy 
seems to be disturbed by the alarm, and imperfect colouring 
is the result. 
As to the form and size of eggs, nothing is more variable ; 
from that which the ostrich deposits in the sands of the 
desert to that of the wren, or the still more minute humming- 
bird, what a difference in size, and, above all, what variety in 
form ! Some experiments, undertaken by M. Geofiroy de Saint- 
Hilaire in Egypt, and by M. Florent-Prevost in France, 
enable them, as they assert, to declare, on seeing an egg, the 
sex of the bird which it contains. After numberless obser- 
vations, they conclude that the globular eggs, that is to say, 
those whose extremities are nearly round, are females, and that 
males come from those more pointed. It appears also, that if 
the void which appears on looking at an egg across a luminous 
body occupies one of the ends, the sex is male ; but if situated 
on either of the sides, it is a female. 
The great variety in their markings has given rise to another 
notion, that the colour of eggs accords with the locality as well 
as the materials of which the nest is composed, and that it is 
intended as a provision for their concealment from those 
animals which prey upon them. This is not sujDported, 
however, by observed facts; nothing can be more in con- 
