Evening star., 1916-06-04

nm HE United States bureau OF nSh-
cries has curious apparatus for
Matching eggs of shad, pike
perch. yellow and white perch and
whitefsh. Upon entering the building
visitors observe a series of large glass
jars set in orderly array on two sides
of a table. and attached to these jars
are several yards of rubber tubing. A
gentle flow of water passes through
the jars, which contain the eggs of fish
in various stages of development.
AS the work in Matching fish eggs in
creased the United States fish commits
sion had demands made upon it which
We're utterly impossible to comply with
by the old methods. Never before in
the history of fish culture was a gov
ernment called upon to deal with mill
lions of eggs of shad and whitefish.
Eventually. because of the enormous
growth in the work. the Mcdonald
automatic Matching jar was improved
and adopted. The feature which so
commends this jar is that it prevents
j., the growth of a fungus which is par
ticulariy injurious to the eggs, more
often killing them than not. The con-
tinuous movement of water through the
mass of eggs makes it impossible for
the fungus to get a start. There is no
dlfflCulty IN keeping a MCDOHalu jar
clean, another point of distinct advan-
tage.
The jar is cylindrical in shape, of good
size, holding seven quarts of water.
The bottom is hemispherical. and stands
solidly upon three knobby glass legs.
A screw top serves as a cap. and in the
surface of this cap, which is of metal.
are two holes. into which glass tubes
are fitted. Through one flows the fresh
water into the jar, and through the
other the waste water is carried.
The first step necessary in setting up
new automatic jar Is a thorough
cleaning 1t is then filled with fresh
water. A shallow funnel made of tin
is put into the mouth of the jar.
through which the eggs are introduced.
If the eggs are taken from transpor-
tation tray, they are generally washed
in by small stream of water, other
wise an ordinary household dipper is
employed to transfer them from ves-
sci to funnel
Large numbers of eggs have been lost
in the past by permitting fish scales or
other foreign particles to make their
escape into the jar, as they seriously
interfere with the free movement or
water and eggs. Not fewer than $4,000
into one jar. 1t is then closed.
Closing Matching Jar Is not so SIM
pie as one might suppose. The water
is turned on and the feed tube intro
duced into the jar. Just as soon as the
feed tube is beneath the surface of the
water in the jar the water is turned
off Unless this is done Immediately
theNbubbles of air from the tube Will rise
and some of the eggs vii escape
through the outlet tube. The water
flows al a pressure of eight pounds per
square inch at the top of the Matching
jar Each jar is supplied with two
quarts of water each minute. The rub
ber tubing which runs from each jar
connects with supply pipes. The waste
water flows off in well constructed
drains.
After the flow of water has been prop
turned over and over continuously. each
having its turn at the top. If 1t is
thought advisable to increase the motion
of the eggs the feed tube is pushed down
to within a fraction of an inch OF the
bottom of the jar. If all goes well no ac-
cidents occur and the jar works as 1t
should. the dead eggs come to the sur
face and remain. These dead eggs, II in
sufficient quantity, form distinct and
the jar Of these eggs, and to do this the
outlet tube is pushed down until the
outgoing current carries them out.
There are times when delay Is un-
avoidable and eggs stand in a jar a quar-
ter of an hour or longer before the
water is admitted In this case the eggs
tend to move in a solid mass. To correct
quickly several times. or until the mass