194 Animal Life 
Water-plants, especially those that grow wnder the water, have a great influence 
on the health of the animals. They give up oxygen to the water, and assimilate 
for their own growth the carbonic acid which the fish exhale. They only do this, 
however, when they are growing in soil. For this, peat-earth mixed with sand and 
loam, or the earth of a molehill, is employed. The layer of earth should be placed 
in the aquarium so that it slopes’ sughtly towards one’ corner. Where it is deepest, 
well-rooted marsh-plants should be planted. Above the layer of earth is placed a layer 
of clean, well-washed river-sand about #-inch deep; this prevents the earth from 
penetrating. In the sand may be set water-plants, such as water-moss, which possess 
no roots, or seedlings of foreign plants with sprouting roots. These seedlings are buried 
deep mm the sand, so that only their tips project, for only that portion which afterwards 
erows im the aquarium 
retains its fresh green 
foliage. Other plants are 
Cabomba cariolana, the 
various varieties of mullfoul, 
etc. Subaquatic plants 
whose roots are only small 
should also be placed 
here. After the bottom 
has been planted, the 
aquarium may be filled 
with water. Where the 
sand is smoothest, a piece 
of stout paper should be 
spread and the water care- 
fully poured in over this 
until the vessel is full. 
Only animals which 
live permanently in water 
are eligible as inhabitants 
of the aquarium. Frogs, 
newts, lizards, tortoises, 
ete., cannot pass as such, 
and must be excluded from 
the list. 
For the beginner, the 
most suitable fish is the 
AQUARIUM FOR TROPICAL FISHES. paradise fish, a native of 
China which has been 
imported for many years, and willingly breeds in the aquarium, building for this 
purpose a nest of froth on the surface of the water. Other delicate fish are 
the various kinds of perch imported from North America, and the canchito, which hails 
from Brazil, whence, of late, its beautifully-coloured cousin, the Brazilian fish, has 
been imported. These both breed im aquaria of larger size, and present a charming 
family picture during the rearing of the brood. Moye difficult of cultivation are the 
different derivatives of the goldfish—the beautiful veil-tailed goldfish, with its widely- 
expanded, ornamental appendage, and the quaint telescope veil-tailed goldfish, with its 
tubular eyes standing far out of its head. Highly interesting but quite small fish, 
newly-imported, are the lively and prolific Girardini, a small variety of carp, of which 
the female is larger than the male. From these a cross has been obtained between 
