THE SWAN AND HER CREW. 



oxygen produced by the plants will keep the water pure, and 

 will supply it with air. 



The green confervoid growth which rapidly forms on the 

 sides of the aquarium must not be all wiped off, for it assists 

 greatly in keeping the water pure and healthy. Tie a piece of 



FRESH-WATER AQUARIUM. 



sponge to a stick, and with this you can wipe it off from that 

 side where it obstructs the view, without disturbing the rest of 

 the aquarium. If you have no cover, and dust accumulates on 

 the surface of the water, it may easily be removed by means of 

 a piece of paper laid on the surface of the water for a few 

 minutes. The dust will adhere to this, and be taken away 



