292 
JOURNAL OS' THE ROYAL HORTICULTURAL SOCIETY. 
useful for the decoration of flower-vases in rooms, dinner tables, 
for church purposes, &c. At first sight one might suppose that 
their habit of shutting up at night would prevent their being 
used for such purposes'; but this obstaclehs got over by a very 
simple remedy, w T hich is to turn back their petals so as to make 
them convex instead of concave. When they are turned back 
after this fashion they keep permanently open until they are 
faded. Thus one sees what glorious opportunities they afford 
to organisers of festivals and for floral work in general. 
The cultivation of hardy Water-lilies is of the simplest, and 
in no way differs from that of the common indigenous N. alba. 
Nevertheless, to carry it out under the best conditions, it is as 
well to use certain precautions which are easily observed. 
Most of the Nymphasas called “out-door,” although nearly all 
equally hardy, frequently differ among themselves in their early 
or late blooming, in their standing up above the water or floating 
on it, in their flowers being many or few, or in their general 
structure and growth being compact or wide-spreading. Some 
of them form strong clumps which constantly increase in 
strength, but do not spread about, whilst others are of a roaming 
nature, their stolons and interlacing rhizomes wandering over a 
large space, and quickly spreading across the roots of other 
varieties. In natural lakes and ponds it is impossible to prevent 
this undesirable confusion ; but this irregular growth should not 
be permitted in artificial basins and aquaria, where each object 
in the collection should remain distinct and thrive indepen¬ 
dently ; besides it would not only produce inextricable confusion 
amongst the plants, but the weaker ones would be infallibly 
smothered by the stronger-growing ones. In order to obviate 
this difficulty it is indispensable that the Water-lilies should be 
planted separately and at proper distances, or else in pots or in 
stonework basins of which the sides and bottom have been 
carefully cemented. 
The form and extent of the basins of water matter little : it is 
optional, according to the taste of the individual grower. Still 
a diameter of over thirty feet will be detrimental to perspective, 
as it will be too far for a clear view. 
It is very important that the basins should be divided into 
several compartments by partitions, which should not be higher 
than three-fourths of the depth of the water, in such a way that 
