ANIMAL STUDY 



Any clear-sided vessel having a large mouth and a capac- 

 ity from a quart up may be used in the study of some form 

 of aquatic life. A more pretentious rec- 

 Vesse i tangular aquarium may be secured at mod- 



erate cost, and with proper care will be an 

 ornament as well as a center of unfailing interest in any 

 schoolroom. Having secured a suitable vessel, place in the 

 bottom a layer of washed sand and gravel. In this place 

 cuttings of swamp grasses, bulbs of the calla or arrow- 

 leaf, or roots of the umbrella plant, if the vessel is a large 

 one. Fill with clear water, preferably from a pond, taking 

 care that in pouring it in the force of the stream is broken 

 so that the material already in the bottom is not disar- 

 ranged. After filling add water milfoil (myriophyllum), 

 or if this can not be secured, any plant that grows with 

 its green part submerged. In the absence of more suitable 

 plants fresh water alga, the green scum of ponds, may be 

 used. If this is used, care should be taken to secure that 

 which is in vigorous growth, as will be shown by its bright 

 green color. The aquarium is now ready for animal life. 

 Certain forms of life, although living in the water, are 

 air breathers, and so do not tend to exhaust the water of 



its oxygen. The aquarium may contain 



Animal 



Life any number of such creatures, consistent 



w^th' the food supply. Turtles, water- 

 beetles, back-swirnmers, water-boatmen, and the larvae of 

 mosquitoes and gnats are of this kind. Turtles exist upon 

 animal food, which should be supplied very sparingly, as 

 whatever is not eaten quickly contaminates the water. 

 They are not ve$y satisfactory animals for the aquarium, 

 unless it is very large. In case they are kept a float should 



