Shepherdstown register. [volume] (Shepherdstown, Va. [W. Va.]) 1849-1955, 1909-04-22
and to supply this and TO simulate natur-
al conditions ''tidal box" is employed.

the tide every five or ten minutes, while
strong currents whirl the water into a
sembIance of wave action and keep the
eggs in constant agitation.
Still another class Of eggs, like those OF
the herring, pike-perches and the stur-
geons, form adhesive masses, which make
them difficult to fertilize and aerate, and
they are usually mixed with little pow
dered starch or muck to destroy their
sickness, after which they are incubated
by one of the methods already described.
During the process of incubation, which
occupies, according TO the species and
temperature OF the water, from three days
to eight months, the fiSh-culturiSt has
ample scope for the application of ex-
perience, skill and good judgment.
Slight changes in the rate of flow OF water,
especially in the later stages, may alter
materially the course of development,
apparently Insignificant variations in the
quantity and quality of dissolved gases
may make or mar the record OF hatchery
and there are always lurking spores ol
bacteria and fungi to plunge the whole
product of seasons work suddenly into
the throes of an epidemic.
The jars and troughs must be kept clean,
and the dead eggs frequently removed,
although with many species there is a
critical period in development when the
eggs can hardly be handled at all without
disaster. All sorts of monstroSitieS, fry
with two heads, two tails, or Siamese
twins, may develop from injurious hand
ling, or from no apparent cause, and to-
ward the end of incubation Matching may
be often expedited or retarded by irregu-
larity in the flow OF water, so that 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 lashing from side TO side within the
shell.
The infant fish just hatched is an awk-
ward, Sprawling creature, but little re-
sembling its parents. Its head is promi-
nent and knobby, with eyes dispropor-
tionately large, its body is long, slender
and transparent, while beneath the belly
is a strange, protruding yellow or whitiSh
bag, covered with branching blood-veS-
sells, the yolk-sac-a most important al
though transitory organ. The mouth is
not yet open, and the fry is therefore in
capable of feeding, although day by day
it grows in size and changes in shape,
gradually becoming more and more like
its parent.
AS the little fish grows, the yolk-sac
becomes progressively less conspicuous,
and the conviction is soon forced upon the
observer that there is some relation be-
tween the two phenomena. The yolk-sac
is, in reality, a food reservoir fabricated
in the body of the parent and stored in
the egg; and the blood-vesSels ramifying
over its surface are the agents by which
il is absorbed and converted into the It's
sues Of the growing infant. About the
time that it finally disappears, in some
species little before and in others later,
the mouth becomes useful organ, and
the baby fish begins to feed, at first on
minute animals or finely divided artificial
food furnished by its foster parent, the
fish -culturist, and later on larger bodies in
keeping with its size. o.
Most species are planted soon after
Matching, or about the time they begin to
feed, although the trout and Atlantic SAL
mon are held in captivity and reared in
ponds until they reach full maturity and
become brood-fish for fresh thousands.
There are fish whose ancestry has been
domesticated and arificially hatched and
reared for generations.
Probably better results would be OBJ
tanned with most species were it possible
to protect the fry until they are stronger,
better able to care for themselves; but
the difficulties attending such an under
taking on such large scale are many,
some of them being created by the un-
grateful conduct OF the fish themselves,
through their proneness to cannibaliSm.
The problems of feeding and providing
sufficient volumes of water are also Sc
rious.
The number of fish spawned artificially
must always be exceedingly small COM
pared with the number spawned naturally,
with the exception in the cases of the
trout and salmon.
The justification and the efficiency oi
fish culture lie in improving upon nature
and securing more complete and eff
cient fertilization of the eggs, in Matching
a larger proportion of the eggs fertilized,
and in protecting the eggs OF the young ir
all stages of development from their many
enemies, from one another and from the
results of untoward physical environment
For this reason the same care must be
exercised in Transporting and planting the
fish as is required in carrying then
through their early development. Some
are planted close to the hatcheries, and
here the principal precaution required is
to deposit them where they are leaS
likely TO be destroyed, either by their en-
emies or by exposure to adverse physical
conditions. A lot Of little lobsters, fol
instance, planted where young pollock
abound would be eaten to almost the las
one, and the labor and expense Of sea-
son would go for naught.
Much care has been expended in per,