The Formation and Management of a Marine Aquarium . 251 
accompanying destruction. One precaution must always be taken, namely, to 
pack the stock in such a way as to lessen to the utmost the probability of 
jarring and attrition; a rough piece of rock, for instance, may chafe a few 
anemones into a lifeless paste in a very short time if in contact with them 
and subjected to the jolting of a fast train. 
In the stocking of a tank, the first essential is to avoid over-crowding. It 
is important also to keep in separate vessels animals that are likely to make 
war upon their neighbours. Little fishes, for example, have but small chance 
of their lives in a collection of anemones : they may at any moment be caught 
by the tentacles and tucked into the appropriating cavity, without having time 
to fight for it or even sigh for deliverance. 
To keep the water bright and always at the same standard of density are 
easy tasks, needing regular attention more than peculiar skill; the deeper the 
vessel the more difficult will it be to maintain in the fluid a sufficiency of 
oxygen. My own idea of a well-managed tank is, that with the exception 
of feeding the animals and a little occasional cleansing, one that manages 
itself—one, for example, that never needs artificial aeration. The removal of 
the dead is of course to be accomplished as soon after a death occurs as the 
fact becomes known. But there may be observed a general languor of the 
inmates ; this will indicate insufficiency of oxygen. The remedy for this is 
aeration. A simple though tedious way of impregnating the water with 
atmospheric air, is to dip with a jug and pour back from as great a height as 
possible without injury to the surrounding furniture by splashing. This should 
be continued as long as possible, and should be frequently repeated. Another 
method is to employ a garden syringe or a common squirt; the instrument 
should be filled and the water ejected into the tank with force, taking care 
that it passes through some space before reaching the surface, in order to 
ensure the entanglement of air with the w r ater ejected ; this also is a tedious 
work and must be continued for a long time and be frequently repeated. 
There is yet a third mode, a self-acting system, which may be kept at work 
day and night, and generally speaking it answers well, Procure any kind of 
vessel of glass or porcelain that can be adapted to the purpose, and that will 
not by its unsightliness make the aquarium ridiculous. It may be possible to 
place it out of sight above the tank in a position where it can be conveniently 
got at as required. The vessel must hold a body of water—say a pint, a 
quart, a gallon, according to the size of the aquarium. It must also discharge 
the water into the vessel below it, in a succession of drops or in a fine stream 
