THE AQUARIUM. 



693 



had for two or tLree hours every morning. In summer the window 

 should be opened, and in the winter evenings the tank drawn back 

 into the room. A south window may be used for the aquarium if care 

 be taken to shade off the noonday sun. When the water at the bot- 

 tom of the tank becomes impure from the accumulation of sediment, 

 it may be drawn off by a siphon (of rubber tube) without disturbing 

 the water above, after which the tank must be filled up again with 

 pure water. For the purpose of removing large substances from the 

 bottom, a pair of wooden forceps — glove-stretchers will do — are re- 

 quired. Light particles, such as uneaten food, decayed leaves, etc., 

 can be removed by placing against them one end of a small glass 

 tube, and covering the other with a finger. The aquarium should 

 be kept as clean as possible, all dead plants or animals being at once 

 removed. 



The best plants for fresh-water aquaria are the spiral Yalisneria, a 

 native of Southern Europe, and not easily procurable ; the American 

 water-thyme (A^iacharis alsinastimm) ; the common frogbit (Hydro- 

 charis morsus-rance) ^ which, being of different form from the others, 

 will give variety in appearance; the arum ( Calla palustris) ; common 

 stonewort ( Chara vulgaris) ; water-soldier [Stratiotes alvidies) ; spiked 

 water-milfoil (Myriophyllum spicatmn) ; small water-lilies (for larger 

 tanks), white {Kymphea cdha)^ and yellow [Nuphar huteum). A little 

 duckweed (Lemna mhi07') may be added, as it floats about and harbors 

 minute insects which the fish eat. In choosing animals for the same, 

 the golden carp is most desirable for its beauty, the minnow for inter- 

 est and longevity. The latter should be examined before admission 



Fig. 4. 



Marine AQDARirsi (Front View). 



and rejected if a white downy spot is observed near the tail, as that 

 is an indication of disease. The loach, the common carp, Prussian 

 carp, roach, tench, and gudgeon, may be admitted, but the first three 

 are preferable to the last. The common tadpole possesses considera- 

 ble interest in its development into the frog. The small newt and the 

 triton are objects of interest and quite harmless. The latter has a 

 bright-yellow body striped with black. "When amphibious animals, 

 such as the newt and frog, are kept, the rock-work must rise above the 



