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Rustic Adornments , 
neria, Stratiotes, etc., etc., and they may all perish. But those Dame Nature 
introduces are sure to live. Being developed in situ they are of constitutions 
adapted to the conditions which exist in the tank, and though it requires a 
long time for a vessel, situated as tins is, to become richly clothed with suitable 
oxygen makers, some supply of oxygen is secured from the very first, for 
we have seen ciliated spores and beginnings of genuine vegetable deposits 
within a few hours of the first furnishing of the tank. Hence it was that 
fortified by previous experiences of the natural system, we did not hesitate to 
introduce the fishes as soon as the tank was furnished, without waiting for the 
full development of the microscopic forest, as we knew that before the fishes 
exhausted the oxygen in the fresh river water, there would be the beginning 
of a new supply for them, and there was never any distress through that pro 
cedure. 
We have italicised above the words “ situated as this is.” The situation of 
this tank is the secret of its success. Near it on one side is a window facing 
west. This window lights the hall abundantly, but very few rays of light from 
it fall directly on the tank. The only direct light which strikes upon the tank 
comes from the fanlight over the door directly opposite, and that is, of course, 
but moderate in amount. Now, in the early days, when we desired a quick 
growth of Oscillatoria, and other oxygen makers, the blind was drawn up at 
the side window, and there was then no fern-case there. The abundance of 
light caused a speedy diffusion and germination of spores, and as soon as it was 
seen that the vegetation was likely to be too plentiful, the blind was drawn 
down, to intercept the light that still came by means of a fern-case. Thus, 
by toning down the daylight, and having the tank where an access of light 
was impossible, we secured a moderate yet plentiful growth of plants, and have 
never had one vegetable filament more than needful, except on the front 
glass, where of course it intercepts the view of the interior. 
Now a word for the fishes. We find that for a vessel of this sort, which 
though to us an experimental and scientific affair is in all other respects a 
piece of elegant furniture, there are no fishes that may be kept with such 
certainty as gold carp. As common carp abound in a pond close 
by, a good many have had temporary residence in the tank. Minnows 
have been used in the same way, and we have also added gold carp, 
and other fishes which are generally tolerably adaptable in constitution. But 
it always happened that when the fishes exceeded a certain number there 
were signs of distress. We could not begin changing the water to obviate this 
