MARINE AQUARIUM. 9 



vessel, and on the surface of the water. To meet this 

 emergency, Mr. Warington introduced a few common 

 Pond- snails CLimneaJ, which greedily fed on the de- 

 caying vegetable matter and slimy mucous growth, 

 so as quickly to restore the whole to a healthy state. 



The result was now quite satisfactory. The plant 

 throve and increased greatly by offshoots and suckers ; 

 the fishes continued to preserve their health and 

 beauty, while the snails deposited enormous masses of 

 eggs, thus supplying food for the fishes, as well as 

 performing the office of scavengers. 



Thus the success of the experiment was esta- 

 blished, and an Aquarium was formed in fresh water; 

 which has continued to prosper to the present time ; 

 the animals and plants maintaining each other in 

 healthy life, and the water preserving its purity un- 

 changed. 



In January, 1852, Mr. Warington began to prose- 

 cute experiments of the same kind with sea-water, 

 which presented some difficulties arising from the 

 compound nature of that fluid, and from the peculiar- 

 ities of marine vegetation. These difficulties, how- 

 ever, yielded to the perseverance and skill of the 

 operator, and while I write these lines. I am a 

 personal witness to his complete success, having just 

 seen (January 1854) specimens of Sea-anemones and 

 other marine animals in good health in that gentle- 

 man's Aquarium, which I know were sent from the 

 sea-side more than a year and a quarter ago. 



A Memoir by Mr. Warington, which appeared in 

 the " Annals of Natural History" for November, 1853, 

 gives some very interesting details of the progress of 



