5O NATURE STUDY 



The aquarium must not be tightly covered over; fresh air 

 must have access to it. 



Do not keep the aquarium in the direct sunlight; it should 

 for the most part of the time be in a shady spot. 



The temperature should be kept, if possible, between 40 and 

 -60 degrees Fahrenheit. Occasional variations, if not too extreme, 

 will not be dangerous. 



Do not put in too many live things; if the aquarium is over- 

 stocked the death rate will be high. 



Keep specially voracious carnivorous insects in an aquarium 

 by themselves with, of course, a supply of food. Do not keep 

 them in the general aquarium. 



Occasionally add a little rain water or clear brook water to 

 the aquarium to make up for the loss by evaporation. 



If you are keeping the immature stages of insects which, 

 when adult, do not live in the water, as dragon-flies, May-flies, 

 etc., cover the aquarium with netting to prevent the escape of the 

 adults and put in a stick or two projecting above the water so 

 that the insects may have something on which to rest. 



With attention to these general directions for looking after 

 the aquarium, and by reference to the special directions for col- 

 lecting, caring for, and observing the various water insects dis- 

 cussed in the chapters on the "Mosquito," ''How Insects 

 Breathe," "Some Water Insects, "etc., the nature study class may, 

 it is hoped, find the caring for an aquarium a matter not too diffi- 

 cult, and in the observation of the life of the aquarium a source 

 of much interest. 



