SCHOOL EQUIPMENT AND ITS MANAGEMENT. 331 



snail of various types, and so on. These, along with water 

 fleas and fresh-water shrimps, may be kept together in a 

 vessel similar to the foregoing. 



In general aquarium jars should be kept away from 

 direct sunlight, e.g. in a north window. They should all 

 contain water weed, of which a variety of kinds should be 

 kept. The weeds not only render the vessels more attrac- 

 tive-looking, but they act as a shelter from too strong 

 light, and to some extent enable hunted creatures to escape 



Fig. 175. Salmon or Trout Boxes. 



In the bottom of each box there is a layer of clean sand. A piece of wire gauze 

 covers the opening (on the inside) of each outflow pipe, preventing the escape of 

 the young fish. A constant drip of water is sufficient. 



when pursued. They further serve the important purpose 

 of aerating the water, and in some cases also serve as food 

 to the inmates of these artificial pools. 



The foregoing remarks apply exclusively to fresh-water 

 aquaria. Marine aquaria are a little, more difficult of 

 management, but for schools situated near the sea these 

 difficulties can be overcome. Teachers desirous of equip- 

 ping a marine aquarium should commence by growing the 

 commoner and more attractive-looking sea- weeds. When 

 these have established themselves, animals such as sea 



