OR, THE HOME-CULTURE OF FRESH-WATER PLANTS. 
cept by themselves, or with snob insects, etc., as are 
intentionally destined to be their food. They are, 
however, very handsome creatures, and so well worthy 
of observation is their structure and habits, that it 
might be worth while to fit up a small Aquarium as 
their especial habitation. Such an Aquarium should 
be covered over at night, as after dark these Water 
Beetles have the habit of quitting the water for a 
night flight in the air, to return to the water again 
at daybreak, a contrast in modes of existence thus 
enjoyed simultaneously, that no other class of either 
insects or animals are endowed with; for the 
aquatic fowl, which have the air also as their 
domain, do not in the water live beneath it, but 
only on its surface. 
The larger kind of Water Beetle, the Hy drophilus, 
piceus, is much less voracious than the preceding 
species, so much so, indeed, that he may be placed 
in a tank with fish and other insects, without much 
risk of mischief, as he lives upon the smaller 
Crustacea and minute animalculae. The larva, when 
about to change, comes out of the water, and bur¬ 
rowing in an adjacent bank, forms the pupa case 
for his change, similar to that of the preceding 
species. 
The larvae of our handsome Dragon Plies are 
103 
