hauls wash out the net so that the meshes 
let the 
Besides the net you want also 
may remain open and water 
through. 
1 thermometer to test temperatures and 
Yottles for sampling water at different 
depths; more extended work would also 
take depths at the different places (sta- 
tions ) tested as well as lines of direction in 
which hauls are made. A microscope, or at 
least a strong magnifying glass, is of great 
Other- 
wise put the mass hauled out into bottles 
value if you are ready to use it. 
with two per cent. formaline solution for 
Be 
properly or give it a number and describe 
future use. sure to label each vial 
the locality, date, depth, etc., under a cor- 
responding number in a note book. 
If you have not the time or the neces- 
sary means to analyze the matter you have 
collected let some one versed in micro- 
scopy or minute life do that part for you, 
or turn it over to some teacher in a uni- 
re to) qos (UI, Sig Ieicln 
Commissioner at Washington. The life of 
versity, or send 
the Swiss and Italian lakes,and of German, 
English and Scandinavian lakes has been 
studied in this manner and largely so by 
Whatever little has 
been done in the United States so far has 
the help of aquarists. 
been mostly through the medium of the 
Fish Commission. 
Let us, too, make some efforts in this 
direction. 
Pointers on Propagation of 
Daphnias or Water Flea 
Frank J. Meyers 
Bethlehem, Pa. 
In order to live, every organism in nature, 
whether animal or vegetable, must absorb 
If we 
closely as possible so that an animal may 
nourishment. imitate nature as 
live in its approximately natural environ- 
ment and feed it the food to which it has 
been accustomed, it is natural that the ani- 
mal will thrive and reproduce its species. 
It is a recognized fact that the best 
possible food for goldfish, especially young 
goldfish, are daphnias. Daphnias in captiv- 
ity die rapidly, necessitating frequent ex- 
cursions to the source of supply by the 
culturist. 
Everybody interested in the culture of 
goldfish probably knows a daphnia when 
he sees one, but a few words explaining 
what a daphnia really is and how it repro- 
duces its kind, may not come amiss. 
Daphnia belongs to the same great class, 
Crustacea, which includes the crab, lobster 
and crayfish, from which, however, they 
differ greatly in size and appearance, tho 
all have a shell or carapace. Daphnia and 
its relatives are placed into a sub-class called 
Entomostraca, which means, in a rough way, 
an insect in a shell. Entomostraca are 
further divided 
several orders, of which 
into 
one is called Cladocera. 
This group includes 
daphnia and others. 
The 
small animal, more or 
daphnia is a 
less transparent, within 
a bivalvular carapace 
hinged dorsally on the 
inside; it has a single 
eye, from four to six 
5} 
feet having branchiae, 
A DAPHNIA 
Greatly enlarged 
or organs of respiration, 
and large, branched antennae acting as 
swimming organs. 
Daphnias are very prolific, the females 
preponderating largely over the males and 
greatly exceeding them in size. Reproduc- 
tion takes place in two ways: 
First, the eggs are received into a large 
cavity between the back-of the animal and 
its shell, where they are hatched and the 
young undergo almost their whole develop- 
ment, so as to come forth in a form nearly 
resembling that of their parent. Soon after 
their birth a molt or shedding of the shell 
takes place, and the egg coverings are cast 
off with it. Ina very short time afterwards, 
another brood of eggs are seen in the cavity, 
and the same process is repeated, the shell 
