The Lee County journal. (Leesburg, Ga.) 1904-19??, 1909-05-21
NEUTRALITY-SUSPICIOUS. 4

nALcneu IN Swallow trays, placed In
troughs of cold, running water.
Shad and whitefish eggs are but
little heavier than water, and are
Matched in jars Of special design, to
prevent massing and consequent suf-
location of the eggs. A current of
water is conducted into the bottom
of the Jars and out of the top, the
whole volume of eggs being kept
In constant circulation, while the fry,
as they are Matched, are automatical-
ly carried over into suitable tanks or
containers.
The eggs of the cod family, the
mackerel family, and some Of the
flatfish, on the contrary, are buoy
ant, and float at the surface of the
sea. These pelagic eggs, as they are
called, when in state of nature, are
particularly well supplied with oxy-
gen, owing to the tossing of the
waves, SO they require special aera-
ton, and to supply this and to simu-
late natural conditions a tidal box"
is employed.
The "TidaI Box"
BY an ingenious application Of the
siphon principle, the water in the
Matching jars or boxes is caused to
rise and fall like the tide every five
or ten minutes, while strong cur
rents whirl the water into a SEM
blance of wave action and keep the
eggs in constant agitation.
Still another class of eggs, like
those Of the herring, pike perches
and the surgeons, form adhesive
masses, which make them difficult 20
fertilize and aerate. and they are
usually mixed with little powdered
starch or muck to destroy their
sickness, after which they are in
cubated by one of the methods al
ready described.
During the process of incubation,
which occupies, according to the spe-
cies and the temperature Of the wat
er, from three days to eight months,
the fish culturist has ample scope
for the application OF experience,
skill and good judgment. Slight
changes in the rate of flow of water,
especially in the later stages, may
alter materially the course of devel-
opment, apparently insignificant var
iations in the quantity and quality of
dissolved gases may make or mar the
record of a hatchery, and there are
always lurking spores of bacteria and
fungi to plunge the whole product of
a seasons work suddenly into the
throes of an epidemic.
The jars and troughs must be
kept clean, and the dead eggs FREE
quently removed, although with many
species there is a critical period in
development when the eggs can hard
ly be handled at all without disaster.
All sorts of monstrosities. fry with
two heads, two tails, or Siamese
twins, may develop from injurious
handling, or from no apparent cause,
and toward the end of incubation
Matching may be often expedited or
retarded by irregularity in the flow
of water, so that the judgment of
the fish culturist is called into play
that he may bring his charges into
the world at the time best suited to
his purposes.
The little fish normally breaks from
the egg tail first, and even some time
before Matching, the hind end of the
body can be seen flashing from side
to side within the shell.
The infant fish just Matched is an
awkward. sprawling creature. but lit
tie resembling its parents. It's head
is prominent and knobby, with eyes
disproportionately large, its body is
long, slender and transparent. while
beneath the belly is strange, pro-
turding yellow or whitish bag, COW
cred with branching blood vessels,
the yolk sac-a most important al
though transitory organ. The mouth
Is not yet open, and the fry is there
fore incapable of feeding, although
day by day it grows in size and
changes in shape. gradually becoming
more and more like it's parent.
AS the little fish grows, the yolk
sac becomes progressively less con-
spicuous, and the conviction is soon
/ forced upon the observer that there
is some relation between the two
/ phenomena. The yolk sac is, in re-
ality, a food rese@voir fabricated in
the body of the parent and stored in
the egg; and the blood vessels rami-
flying over its surface are the agents
by which it is absorbed and convert
ed into the tissues of the growing
infant. About the time that it final
ly disappears, in some species little
before and in others a little later,
the mouth becomes a useful organ,
and the baby fish begins to feed, at
first on minute animals or finely d.