206 THE AMERICAN NATURALIST. 
on first setting up the aquarium, and as this is one way of 
obtaining certain desirable results, keep it covered until the 
foul odor disappears, and if new plants do not appear in time, 
add plants and animals to suit, and it may prove to be the best 
aquarium you have. Marine Protozoa have been kept this way 
in jars brought from the seashore several years ago. 
CENTRAL HIGH SCHOOL, 
DETROIT, MICH. 
