176 WATER-LILIES 



arrangement also greatly facilitates rapid 

 ventilation. 



For the water supply there should be at 

 least two taps in the main basin both fitted 

 with a screw attachment for hose connection. 

 Fountains are not to be advocated. They take 

 too much space and the water drops are likely 

 to cause spotting in the Nymphaea blossoms. 



For drainage an automatic coiie-lid pipe 

 is of greatest advantage. At least two lower 

 holes must be provided so that in the early 

 stages the water level can be kept low, and 

 yet the pond can be flushed. A large drain, 

 to be closed during the summer, is placed at 

 the bottom of the Victoria pond. This 

 enables one to clean the pond thoroughly 

 after the removal of the water plants. In- 

 stead of simply running off the water from 

 the tanks into drains it will be found advan- 

 tageous to allow it to supplement the water 

 in an out-of-door pond or an artificial bog, 

 both intended to accommodate hardier plants 

 and which can be located in the immediate 

 vicinity of the greenhouse. Even the hardier 



