178 STOVE PLANTS. 



the water, and this is best efiected by providing that a 

 current should run through the tank to carry away the 

 confervoid growth which is sure to show itself, causing the 

 surface of the water to be very unsightly. The same 

 means wiU also serve the purpose of keeping the main 

 body of water at a proper temperature. For the purpose 

 of securing this motion some use a wheel, but this has 

 always seemed to us a clumsy contrivance, and we have 

 seen used in preference a small pipe, with a broad spread- 

 ing nozzle, which is so placed as to rise a little above the 

 surface and to point downwards, by which means, when the 

 water is turned on, it agitates the whole mass, and produces 

 a current throughout the tank, the surplus water being car- 

 ried off by means of a waste-pipe fixed at the opposite end or 

 side. In treating of the Victoria (page 181), we recommend 

 several levels for the water, according to the size of the plant. 

 In order to secure this, and to be able to run off surplus 

 water, the waste-pipe must be made in lengths and jointed, 

 so that when a rise of water is needed a joint may be screwed 

 on, this being repeated as required until the top of the tank 

 is reached. Such exotic ferns as Acrostichum aureum, being 

 semi-aquatics, may be grown in association with the true 

 water plants. 



EUETALB. 



E. ferox. — This is a very elegant plant, with large peltate- 

 orbicular leaves, covered on both sides with long spines. 

 The flowers are scarcely as large as in Nymphma carulea, 

 and are of a deep violet colour. It requires to be treated 

 in the same manner as Nymphma, but, as it is an annual, 

 some of the flowers should be fertilised, to insure seeds 

 for the following season. Native of lakes in the East 

 Indies. 



