72 FKESH-WATEE AQUAEIA. 



are of two different shapes : the upper leaves are three-lobed, 

 with rovinded notches, and float upon the surface of the water ; 

 the lower ones are divided into numerous hair-like segments, 

 and are always submerged. In quickly-running streams the 

 floating leaves are generally wanting. The rather large flowers 

 are white with many yellow stamens, very like sti-awbeiTy 

 blossom, and are borne from May to September. The Water 

 Crowfoot is a most useful plant to the owner of an aquarium ; 

 for it will grow extremely well in a tank, and in its masses under 

 water much interesting animal life is almost certain to be found. 

 If a healthy portion of this plant is cut off, so that it is just 

 long enough to allow the flowers and the lobed leaves to float 

 on the surface of the water while the severed end touches the 

 bottom, and is then tied to a stone and sunk in the aquarium, 

 it will quickly take root and grow; indeed, so rapidly will it 

 increase, that care must be taken lest it usurp the entire tank. 



The Ivy-leaved Crowfoot {Baminculus hederaceus) is a very 

 useful little plant for the aquarium, especially for those which 

 are not deep. In some neighbourhoods this weed is very 

 common, and is to be found growing in shallow water, on the 

 sloping margins of ponds, and on those places from which the 

 water has lately retired. This plant is not nearly so large as 

 the Water Crowfoot, and its flowers are very small. It has a 

 creeping, submerged stem, throwing out roots, and its leaves 

 are roundly lobed, rising on rather long stalks some little 

 distance above the surface of the water. Any portion of the 

 stem having leaves attached will grow and blossom freely in 

 an aquarium. 



Water Lobelia {Lobelia Dortmanni) is a very pretty and 

 suitable plant for the aquarium, but it is not readily to be 

 procured, as it is almost confined to the northern lakes, where 

 it grows in thick masses at the bottom of the water. Its flowers 

 are light blue, and grow droopingly upon long stalks, which 

 rise above the surface of the water, and its leaves are long and 

 narrow and almost cylindrical. This plant may be set in the 

 sand and gravel of the aquarium. 



The LUy-like Yillarsia [Villarsia nymphceoides) (Fig. 53), 

 named in honour of M. de Yillars, a French botanist, is a very 



