GOLDFISH 



447 



dormant in winter and has only decorative value at that period. 

 Liidwigia, Ludwigia gJandulosd (fi<;. 6), is hifj;hly prized for its 

 tine appearance in the aquarium and is easily propagated from cut- 

 tings. 



Fig. 2. — Fanwort {Cabomba carollniana) . Natural size. Found in ponds and slow 

 streams, southern Illinois to North Carolina, south to Florida and Texas 



BALANCED AQUARIUM 



When the relations of plant life and animal life in an aquarium 

 are properly proportioned, the aquarium is said to be self-sustain- 

 ing or balanced, and under such a condition the water requires no 

 change. Filling in to make up for what has evaporated is all that 



