400 



NATURE STUDY AND LIFE 



How to set up or fill the aquarium for general purposes 

 is the next topic. First put in about two inches of sand, 

 washed until a stream of water runs off clear; then, 

 with the sand only moist, set the plants about the corners, 

 making furrows in the sand in different directions and 

 laying the roots in them ; finally, arrange pebbles, shells, 

 and larger stones about the bottom where they will 

 keep the plants in place. Next pour in the water up to 



within an inch 

 of the top, hold- 

 ing the hand or 

 a piece of thin 

 board so as to 

 break the force 

 of the stream, 

 and avoid wash- 

 ing the plants 

 loose. Finally, 

 put in a fresh- 

 water clam or 

 two, some snails, 

 a few tadpoles 

 (if the fishes 

 will allow of it), to keep the water clean, and, after a day 

 or two, such fishes — not more than two or three — as it 

 is desired to study. Overcrowding is the common temp- 

 tation to be resisted. Allow one gallon of water to each 

 fish three inches long, and where enough water plants are 

 present to oxygenate the aquarium, the fishes will show by 

 their actions, quiet movements, and breathing that they are 

 comfortable. If they come to the surface and gasp for air 



Fig. 162, A Frog with Six Legs 

 A curiosity for the aquarium 



