The Ohio Democrat. (Logan, O. [Ohio]) 1886-1906, 1889-04-13
ABOUT BIRDS. EGGS.
Interesting Facts Concerning Their Com
position and Formation.


Eggs are composed of two principal
parts, termed, from their color, the
yelk or vitellus, and the white or al
bumen. The latter does not exist in
the ovarium or egg-bag; there, as we
may see in almost every fowl that
comes to the table, is also q numerous
collection of yelks of various sizes.
When these are fully developed, they
drop, one by one, through passage
termed the oviduct into the uterus, in
which the egg is perfectly formed, hav-
ing collected its albumen or white and
is ultimately expelled.
The very expeditions growth or pro-
duction of the white of the shell is an
extraordinary exertion of nature-a
very few hours only being sufficient to
produce it. The texture of the shell is
admirably calculated for preserving
the contained parts, and for retaining
the heat that is conveyed to them by
incubation. Immediately under the
shell is the common membrane which
lines the whole cavity of the egg, ex-
cept at its broad end, where there is a
small space filled with air. Within
this membrane, the white, which is said
to be of two kinds, is contained; and
near it's centre, in an exquisitely fine
membrane, is the yellS, which is spheri-
cal, while the white is of the same
form as the shell. At each extremity
of the yolk, corresponding with two
ends of the egg, is the chalaza, white
firm body, consisting of three bead-like
globules, and it is at these points that
the several membranes are connected,
by which means. in whatever position
the egg may be placed, its various parts
are retained in their proper place.
Near the middle of the yelk is a
small, fiat, circular body, named the
cicatricula, in which the rudiments of
the future chick are contained; and
from these, in consequence of incuba-
ton, or from a certain degree of con-
tinued heat of any kind, the bird is ul-
timately Matched. In this process the
germinal membrane, as it is called, or
rudimental parts of the chick, is OBJ
served to become separated into three
layers, from the external layer of which
are formed subsequently the osseous
and muscular systems, and the brain,
spinal cord and nerves; while from the
middle and internal layers are formed
respectively the heart and blood ves-
sells, and the intestinal canal and it's
appendages The yelk and white of
the egg gradually become thinner. sup
plying the growing chick with nourish-
ment, which, increasing in magnitude,
at length bursts its cell and comes
forth, still retaining in its intestines a
portion of the yelk to serve for its sup
port until its powers are sufficiently
vigorous to enable it to digest extrane-
Gus food.
1t is a remarkable fact, that those
birds, the nests of which are most un-
covered, and the eggs of which are
most exposed to the sight of their enc
mics, lay them of color as little diff
ferent as possible from surrounding
objects, so as to deceive the eyes of de-
structive animals; whilst, on the con-
trary, those birds, the eggs of which
are of n deep and vivid color, and con-
sequently very liable to strike the eye,
either hide their nests in hollow trees,
or elsewhere, or do not quit their eggs
except at night, or commence their in
cubation Immediately after laying. 1t
must, moreover, be remarked, that in
l,n Of oh
exposed, if the females alone sit on the
eggs without being relieved by the male,
these females have generally different
color from that of the male. and more
in unison with neighboring objects.
Pure white, the most trcacherous of
colors, we find to be the color of the
eggs of birds which build in holes, as
the woodpeclers, the kingfishers, the
swifts, the dock and water swallows,
and others; also of those birds, as the
titmice and wrens, which construct
their nests with openings so small that
their enemies can not see into them.
Moreover. we find eggs white in birds
which do not quit their nests, except
at night, as the owls; or for a very
short time during the day, as the fall
cons. Finally, this color is found in
those which ray only one or two eggs,
and which Immediately begin to sit, as
the pigeons, etc.
The clear green or blue color is
proper to the eggs of many species
which build in holes, as the starlings,
the iy-catchers, ETC.; it is also common
to the eggs of birds the nests of which
are constructed of green moss, or situ-
ated in the midst of grass. but always
well hidden. Green eggs, too are found
with many powerful birds able to de-
fend them, as the herons.
A faint green color, approaching to
a yellowish tint, is observed in the
eggs of birds. as the partridges and
pheasants, which lay in the grass, with
out preparing a regular nest. The same
color is remarked in those which cover
their nests when they leave them, as
the swans and the ducks.-N. Y. Led