Year: 1867

The structure of the eggs of birds offers
certain resemblance to some forms of the
galvanic battery. inasmuch as they consist OF
fluid enclosed in a porous daphram. and
IN contact with another fluid Of different
composition. This circumstance, attracting
the notice Of DR.. John Davy, he made it
the subject of more careful experiments, in
order to ascertain whether any galvanic nc.
ton was exerted by the different constituents
OF winch the egg is composed. The result
OF his experiments fully justified his cxpec.
tations, and established the fact that electro
chemical action plays no unimportant part
IN the changes which the egg undergoes
during the process of incubation. lie found
that this action was sufficient to defect the
needle of a delicate galvanometer fully five
degrees, and that in changing the wires the
needle was reversed


DIR. j. V. c. Smith has recently deliver
ed very interesting address before the
American Institute, at New York, on the
: Structure of Eggs" which was listened
to with great attention, and which contains
a statement of many facts which are both
new and interesting. The Doctor remarked
that in one sense it might be said that all
animals. from the mole to an elephant, are
the product of an egg. though there are
many varieties. In poultry. food can add
to the number of eggs, for they are created
with life itself, and lie in embryonic state.
Scraps Of meat and like food only furnish the
material which forms the fluid part of eggs
in the winter season. Young birds, when
fed on worms grow faster for Il few weeks
than they afterward do when they get grain
or seeds


DR.. Smith then showed vertical section
drawing Of an egg, with the germ Il speck
on the upper side Of the yolk. From the two
poles OF the egg, what amounts to a cord runs
through the centre of the yolk, aud holds it
suspended in the white. In turning the egg,
this cod may lie twisted any number Of
times. and yet such is its nature, that the
germ will always be on the upper side
Philosophers have repeatedly tried to make
the germ lie on the lower side Of the y0lk,
but they found it impossible. In Matching,
the bird turns over the egg frequently, that
the white may be equally warmed but the
germ always will be nearest her body.


The eggs of fish also are constructed in
this manner, that they may have. the advan.
tage Of solar heat. The eggs of the skate
present some wonderful features, for the
cords are so constructed that if they tip over
in storm the heat of the sun will shlivel
the side most exposed, when the egg will
light itself and get the sola: heat.


Around the germ of the egg the white is
collected, and forms the body of the Bird
A short time before the bird is hatched there
is "a hole in its breast, and at a particular
period the yolt enters into this hole, with n
species of spasm, when the or.ice rapidly
heals over. Then on the end of the bill
there Is Il little sharp horn, which the young
bird uses to crack the SHE'LL and to open its
way into the outside world Being no longer
of use, it soon drops of.


Now this y)lk contained within the crop
and body Of the young bird, is to furnish it
with the nutritious food most proper for i
More than this, il is blind but, when the
yulk has been consumed. then its eye>ight is
established. The parent is aware Of this
fact and at first does not seek for food but
So she thinks its store is exhausted,
she scratches Il little at a time, and when its
young can see. it will pick up with the bill
what is provided. We should he taught by
this that great harm can be done by giving
food to young chickens while the yolk yet re.
mains in their crops; and perhaps we now
understand why so many die young