TROPICAL AQUARIUM FISHES 15 
Vallisneria, or other rooted plants, and spread them out well. (See 
chapter on Plants.) After the proper arrangement of plants is made, 
add from an inch to two inches of sand and pebbles, being careful not to 
completely cover any of the leaves. Now fill the aquarium and with a 
slender stick lift up any leaves which have been held down by the sand. 
After the leaves have been brought into an upright position, take hold 
of them and pull upwards until the crown of the plant comes just to the 
surface of the sand. Aquatic plants with crowns seem to do better if 
the crown is not quite covered. The crown is the point from which the 
leaves put out. 
Care should be taken in planting not to allow the leaves to become 
even partially dry. This can be accomplished by frequent sprinkling, 
and the work should be completed as rapidly as possible. 
Bunches of Cabomba, Anacharis and other plants, can be added last. 
These need to be weighted down with bits of lead or tin wire. In filling 
the aquarium it is a good plan to place a piece of paper in the center of 
the aquarium and let the water strike on this. By this method the plants 
will not be seriously disturbed. The use of a watering pot for filling will 
also prevent any serious disturbance of the planting. The aquarium 
should be allowed to stand at least a day before the fish are introduced; 
but a week would be better, so that the plants may become active in time 
to be of real use to the fish. 
The use of pebbles only in the bottom of an aquarium is not to be 
recommended, because particles of food may fall between the stones 
where neither the fish nor snails can reach them, and the decomposition 
thus set up is liable to foul the water. 
Testing Aquaria. Before putting plants or sand in the aquarium 
it is well to test its tightness. More often than not the larger sizes leak 
after removing or standing dry. These leaks can usually be corrected in 
a few days by filling with very muddy water, stirring it occasionally. 
Fish Globes. Ignorance is responsible for most barbarity, and one 
of the commonest forms of both is the keeping of fishes in globes. The 
globe is in every way opposed to the correct principles of aquarium- 
keeping. When it is filled, the air surface of the water is extremely small 
in proportion to the bulk of water. The convex form acts as a lens to 
perpetually focus light into the eyes of the fish. Even the side light of a 
straight-side aquarium is known to be less desirable than top-lighting in an 
opaque tank. What then must be the effect of a focused side-light? A 
proper plant growth in a small globe is almost impossible. All of these 
evils are multiplied by the apparently universal over-crowding in these 
