Plankton 
Eucene Smiru 
Hoboken 
When you look into deep waters from 
shore or from shipboard you rarely see 
more than the reflection of the sky in its 
varying moods, or perhaps only one uni- 
form dark mass of water. You know, of 
course, that there are fish there as well as 
other living things, but of the vastness of 
that life, few have any idea. 
There is not a drop of that water which 
is not literally quick with animal and vege- 
table life. The word Plankton is of Greek 
origin and signifies “that which floats.” It 
includes all this manifold life of the water 
which is not attached to the soil or which is 
not to a large extent free of the sway or 
current of the water. It includes what has 
motion of its own as well as that simply 
borne along by wind and wave. 
The actively swimming part is also 
called the nekton or swimming, while the 
plankton proper is that more at the mercy 
of the water, the drifting. All classes of 
life are represented. 
Thus among the nekton are wandering 
polyps, worms, snails, rotifers, many 
rrustacea like daphnia, cyclops and others, 
bryozoa, protozoa and others, the larve 
and pupe of many insects, the adults of a 
few only. 
Among the plankton proper: are also 
5 
protozoa, eggs of many kinds, including 
those of fishes and very largely alge and 
other plants either freely floating like the 
sargasso weed, the blue-green alge caus- 
ing the bloom of the water, or the much 
minuter diatoms, etc., as well as spores 
and seeds. 
The of the called 
halobius, that of the freshwater /imnobios. 
The amount of this floating life is simply 
plankton sea is 
inconceivable both as to kind and quan- 
tity, and it is just this that makes possible 
the immense productivity of the water in 
higher, i. e. to say, vertebrate life, as it 
furnishes food to it. 
The plankton varies as to its composi- 
tion and amount according to season, direc- 
tion and force of wind or current, depth 
of water, distance from shore, plentitude of 
certain organisms as attraction for others 
and for innumerable local reasons, having 
thus maximal and minimal phases; period- 
Much 
remains to be done to clear up this life of 
the of 
many to help in this field. 
icity, annual, monthly and daily. 
water and it is within the reach 
The apparatus for this work are few and 
A of fine silk 
mounted on a ring or spreader of about 
simple. net made gauze 
eight to twelve inches opening. The bag of 
the net should taper from this width to a 
point at the end where it may either be 
tied with a string or provided with a smaller 
frame covered with gauze or have a small 
bottle or detachable box attached to hold 
The 
net is drawn through the water in tow of 
what is sifted out from the water. 
a row-boat or a slowly moving motor-boat, 
and after covering a certain distance is 
hauled in and emptied of its contents, 
either by scraping the _ jelly-like mass 
out of the net or by dumping the de- 
tachable bottle into a vessel held ready 
for the purpose. The bag should be from 
one to two feet in depth. The towing line 
should be made of strong linen cord and 
at least twice as long as the greatest depth 
to be operated in. To use the net one man 
may row the boat while the other manages 
the net. 
weight or more to the end of the line and 
For deep -hauls attach a pound 
the net at whatever height above the bot- 
tom you wish to explore. The weight 
drags along the bottom until you haul up 
the whole to empty it and proceed again. 
It is well not to make too long a haul, as 
the gauze becomes easily clogged with the 
plankton. 
For shallow depths or for surface tow- 
ing the weight may be dispensed with en- 
tirely,or to give the net a little steadier pull 
a light weight may be attached to the line 
-several feet in advance of the net. Between 
