REARING INSECTS IN THE SCHOOL-ROOM 



49 



tumbler or fruit jar, into which a few water in'sects, snails or min- 

 nows have been put, for present observation. For the permanent 

 aquaria something more is necessary. If a large rectangular 

 aquarium case, of glass and wood, or glass and metal, cannot be 

 bought or made, then get two or three large "battery -jars," 

 cylindrical jars of large diameter and no neck, or specimen jars. 

 Each of these jars may be transformed into an aquarium. (See 

 fig- 25). 



Put first a layer of 

 sand two inches deep 

 into the aquarium (the 

 large rectangular one or 

 the smaller cylindrical 

 one) at the bottom; put 

 over this a thinner layer 

 of small pebbles with one 

 or two larger ones; then 

 plant in the sand a few 

 water plants (necessary 

 to keep up a supply of 

 oxygen in the water). 

 Now put in the water 

 and finally the water ani- 

 mals especially desired 

 to study, with a few 

 others for the sake of va- 

 riety or to serve as food. 



Elsewhere in this series of nature study lessons I shall give 

 an account of some water insects which may be kept in the school- 

 room aquaria, so that here only the special care of the aquarium 

 as a whole will be discussed. The following points should be at- 

 tended to: 



There must always be growing plants in the permanent stag- 

 nant water aquarium. 



Fig. 25. Bat tery Jar Aquarium 



