152 WATER-LILIES 



depth of water must be increased. Ordi- 

 narily this amounts to about one inch every 

 three or four days. Finally the water-level 

 should be about eighteen inches above the 

 crown of the plant. 



If there should be a decided fall in the 

 temperature of the atmosphere during the 

 first few days after planting special arrange- 

 ments, such as screening, must be made to 

 protect the young plants. 



By the end of July the plant will have 

 grown to such an extent that it needs the 

 freedom of the outer pond, as up to this time 

 its growth is confined to the inner tank. The 

 water-level must be raised to such an extent 

 that the inner and outer basin become as one. 

 The heating of the inner basin is continued 

 as before. 



The raising of the water level must be as 

 gradual as before. Having raised it first of all 

 an inch above the rim of the inner basin, it is 

 increased till the desired height of the water 

 has been reached, that is to say, about twenty- 

 four inches above the crown of the Victoria. 



