FRESH-WATER AQUARIUM. 61 



The American Frog-bit [Limnobium sjpongia) is the 

 same as the European plant Hydrocharis and is found in 

 the northern United States ; it is said by English natural- 

 ists to be a good plant for the Aquarium. From not 

 having been able, as yet, to find it, I cannot say whether 



it be or not. 



There are many other plants which may be introduced 

 into the Aquarium; but those I have given are the most 

 common and easily obtained. I generally plant Sagittaria 

 in the centre (removing it after a time, as it dies 

 down when the flowers go off), and place Ccratojiky- 

 hm and Nitella around, whilst on the surface, I throw Cal- 

 litride Anacharis and Lcmna, the latter of which soon 

 multiplies and covers the surface of the water. One of the 

 prettiest arrangements in a fresh-water Aquarium is to 

 have a good sized Nitella, with its light and transparent 

 green stalks set off by a dark bunch of Hornwort placed 

 as a background, for in an Aquarium as much taste may 

 be shown in the grouping of the plants and animals, as 

 in the arrangement of a picture ; and nothing looks worse 

 than to have the plants thrown in pell-mell, to take their 

 own chance of arrangement. 



