PLANTS FOR. 25 



and present thread-like divisions, spreading in 

 all directions ; another set float on the water, 

 and have three lobes. In this instance we have 

 an arrangement to meet the requirements of the 

 plants : those leaves which are exposed to the 

 air have the ordinary structure of aerial leaves, 

 whilst the others are divided according to the 

 general plan of the leaves of aquatic plants. 

 There are several other species of aquatic Crow- 

 foots, but none of them are so common as the 

 above. Other species of Crowfoots, as Ranun- 

 culus Lingua and Ranunculus Flammula, grow 

 in ditches and lakes, and might doubtless be 

 cultivated successfully in shallow tanks. 



WATER LILIES (Nymphceacece). Two Water-lilies, 

 the white (Nymphcea alba) and the yellow 

 (Nuphar luteum) grow in Great Britain. Either 

 of these are handsome ornaments in an Aqua- 

 vivarium, but they require a large vessel and a 

 good deal of soil in order to attain perfection. 

 Their leaves are very large, and die down in the 

 winter, and thus produce much refuse. Where 

 tanks of large size can be commanded, not only 

 may these beautiful plants be grown, but their 

 foreign allies, as the species of Euryale, and even 

 that queen of the waters, Victoria regia, may be 

 attempted where there is heat sufficient. 



The COMMON WATER CRESS (Nasturtium qfficinale) 

 belongs to a family of plants, the Cross-bearers 

 (Cruciferce), many of whose members grow in the 

 water. No one would think of growing water- 

 cresses for breakfast in a drawing-room, although 

 this might most certainly be done; but the water- 

 cress may be cultivated for its use in the Aqua- 

 vivarium. A few seeds buried in the soil at the 

 beginning of the year soon spring up, and give a 

 very pretty green appearance to the bottom of 



