THE FRESH-WATER AQUARIUM. 31 
upon the surface. When you have secured as many com- 
plete plants as you require—and two strong stems will be 
enough for any tank—pick off a dozen or more blossom- 
heads, taking each at a clear jomt. When the roots are 
planted, sprinkle the short flowering tops over the surface, 
and you will have at once a wide spread of snow-white 
flowers that will continue gay till the end of the summer, 
while the fixed roots will give a graceful efiect to the 
vegetation of the mid-water. 
Hydrocaris morsus rane, or the 
common frog-bit, may be obtained of 
the dealers, and is common in brooks 
and rivers. It is a perennial, inter- 
esting in its growth, very curious 
when in flower, and a good maker of 
oxygen. 
Alisma, of several species, may be 
obtained from brooks and rivers in 
plenty. It is the Water Plaintain of 
the old botanists, and has an ancient 
renown, which cannot be dealt with 
here. The long stems and lanceolate 
leaves of this genera give a pleasing 
variety to the vegetation of the tank. 
Lemna.—The four English species may be used to 
advantage. If the whole of the surface be covered with 
the pretty grass-green fronds of this very common plant, 
the effect is good, and it gives a salutary shade to 
the finny creatures. A single frond thrown in will soon 
spread and cover the tank in time, and its growth cannot 
HYDROCARIS 
MORSUS RANA. 
