278 POPULAR HISTORY OF THE AQUARIUM. 



* Zoologist' for 1854. Being drawn up from actual observa- 

 tion, it is better than a florid description would be. 



" We have, for some time past, kept a glass trough filled 

 with aquatic plants and animals ; the bottom of this vessel 

 is covered with mud, and the rockwork filled up in the 

 centre is overgrown with a delicate, hair-like conferva ; a few 

 floating plants spread over the surface of the water, and in- 

 numerable Eiifomostraca, and other sm.all crustaceans, as well 

 as various animalcules, swarm in all parts; the minute but 

 deadly poison-armed Hijdra also prevails where food is so 

 plentiful; and a solitary individual of the great water-beetle 

 rambles over its watery domain, lord and master of all. 

 Several of the fresh- water MoUusea also people the trough, 

 which on the whole has very much the appearance of a 

 miniature pond. Into this home were put four or five Stickle- 

 backs last May, and they at once made themselves perfectly 

 at ease. One, without the least hesitation, took possession 

 of a certain spot, which it^guarded with the greatest tena- 

 city, attacking vigorously any of its companions that might 

 happen to approach the chosen locality. The Beetle too, 

 which sometimes came paddling slowly by, was pounced 

 upon and unceremoniously tumbled over, but, secure within 

 his scaly armour, as the knights of old^ he little heeded the 



