OB, THE HOME-CULTURE OF FRESH-WATER PLANTS. 



cept by themselves, or with such 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, iheHydrophilus, 

 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 animalculse. 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 



