198 THE AUSTRALIAN NATURALIST. — 
native fish also require careful handling, as they are very apt to 
become covered with a parasitic fungus (Saprolegnia), due, I 
should say, to the change of the temperature of the waters when 
transporting. Fungus is the effect of illness, not the cause. 
As fish-tanks, accumulator jars were much used when they 
were easier to procure, but their faults were many; being of 
blown glass. they are always apt to flaw, the crack formed ex- 
tends, and when it once reaches the top, it’s all up. The glass 
itself is uneven, but the main disadvantage is that they are by 
far too deep. A tank for fish should never be deeper than the 
width of its narrowest side, We should always seek nature’s 
guidance. : 
The round fish bowls are in every way opposed to the correct 
principles of Aquarium keeping. They are far better throwa 
away than used, even as an emergency. The surface of the 
water is extremely small in proportion to its bulk. ‘The convex 
shape acts as a lens, and distorts the fish, but this is nothing com- 
pared to the misery to which you are subjecting your fish; the 
convex shape also acts as a lens towards the inside of the bowl, 
and focuses the light into the very eyes of your fish. Throughout 
the most miserable existence we could give our beautiful little 
pets which under natural conditions only receive top light. 
ALWAYS remember a fish has a nerve system; it has a feeling 
as well as you and I. If we are going to deprive them of their 
liberty, let us give them all the comfort we can, and not make 
their existence one of cruel discomfort. “ 
Anyone handy with tools can make his own tanks. A useful 
size is 15 inches by 9 inches with a depth of 9 inches. An inch 
or so of sand and grit as a foundation to root the plants in 
gives a smaller depth than the width. Paint, clean, and soak 
well. Fill the bottom of your tank to the depth of an ineh and 
a half, with sand and shell-grit which have been thoroughly wash- 
ed; into this plant your plants, fill with water, but so as not to 
uproot the plants; let stand for a few days, and then the fish 
. ean be introduced. \ 
T have used pure sand, but found that it packs so densely 
that the slender roots of the plants cannot penetrate, and there- 
fore do not flourish. Never make use of garden soil unless you 
want endless trouble. ; 
Plants used should be those of submerged habits; floating 
plants and the kinds which grow above the water produce very 
little oxygen, if any, below the surface of the water The most 
