FISHES AQUARIA 167 



in this way, only needing the addition of water now and then 

 to make up the loss from evaporation. 



Water milfoil, eelgrass, elodea, and filamentous green algae 

 are very good plants for aerating the aquarium water. Other 

 plants may be added for beauty. The little floating duckweed 

 is an interesting plant to have in an aquarium. Another 

 interesting and curious plant is the water hyacinth, which 

 may be obtained from greenhouses. With its thickened leaf- 

 stalks, which contain air, it floats on the surface of the water. 



Plant small varieties of bullrushes, water buttercups, arrow- 

 head, small swamp sedges, marsh marigold, and other water 

 or marsh plants, in the sand at the bottom of the aquarium, 

 or at the edge of the water in a terrarium. This is simply a 

 cage, with earth floor, for land animals. If a basin of water 

 is set in this soil, both land and water conditions will be 

 afforded. Frogs, toads, salamanders, turtles, snakes, and 

 other animals prefer this kind of cage. It should be orna- 

 mented and made more natural by planting land and water 

 plants as suggested. 



Another suggestion for the aquarium is that an island be 

 built of stones or earth for the benefit of turtles, frogs, and 

 other animals that like to crawl out of the water. Plants 

 may be placed on it also. 



As an aquarium should not be too much in direct sunlight, 

 any other window except a south window is suitable. 



If an aquarium becomes coated with an incrustation, this 

 should be removed by scrubbing. 



In case it becomes necessary to change the water of an 

 aquarium on account of stagnation, it should be done by 

 avoiding too great change of temperature. The water 

 probably has the temperature of the room, and the fishes 



