296 
JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
afterwards I received a memorandum informing me that the 
package had been found, and asking me what should be done 
with it. Feeling certain that the plants would be dead, I 
ordered them to be sent back by slow train ; but on their arrival 
I was utterly astonished to see them in good order and covered 
with shoots, and very little the worse for being so long boxed up. 
To show the advantage of the endurance of Water-lilies I ought to 
add that I have thrown waste plants on to the earth surround¬ 
ing the ponds, and have found their roots still quite sound after 
having lain six months on the open ground. 
Cultivators of aquatic plants have often shown great anxiety 
about the supposed havoc caused by water-rats and mussels ; also 
by different kinds of insects, fish, &c. I think that tlieir fears have 
been exaggerated, because for my part I have only had to 
complain seriously of the ravages committed by two kinds of 
larv®, the one black and the other white, produced by certain 
small yellowish-white butterflies which deposit their eggs on the 
floating leaves. These larvae, at first almost invisible, grow to 
about the thickness of a wheat straw, and devour the leaves of 
the Lilies during the night; also those of the Aponogeton, 
Limnocharis, &c. They are very clever in hiding themselves 
during the day, laying fragments of the leaves on their bodies 
and covering themselves up with pieces of Lemna palustris or 
Azolla. Their devastation would be serious if it could not be 
easily stopped by pouring on the surface of the water some drops 
of a mixture of three-quarters colza oil to one-quarter of paraffin, 
a sufficient dose to poison and destroy them without hurting the 
plants. The climatic conditions of England are without doubt 
inimical to the existence of these voracious larvae; but, in any 
case, I have pointed out the infallible means of suppressing 
them. 
I should not bring this dissertation on Water-lilies to an 
end without bestowing a few words on the splendid section of the 
Cyanea, or blue Water-lilies. It is greatly to be regretted that 
hitherto all attempts to cross them with their hardy congeners of 
the northern hemisphere have so far failed. It would be a great 
triumph to add to the already sumptuous collection some hardy 
hybrids of a sky-blue colour with a delightful perfume. They 
are very variable, as from the seed of N. zanzibarensis one can 
obtain the most beautiful colourings of deep blue, tender blue, 
