240 THE WATERLII.IES. 



flower should also be kept netted before and after it opens ; this is to 

 avoid any mixing of pollen by insects. Now, on the day the seed-flower 

 first opens, the net is removed for a moment while, with a brush, pollen 

 from the chosen male parent is stirred around in the stigmatic fluid. The 

 net is replaced, and in a week or so the result will be indicated by a 

 swelling of the ovary if successful, or by decay of the flower and peduncle 

 if no fertilization was effected. Some consider that the pollen should be 

 applied at the close of the first period of opening of the seed-flower. I 

 have succeeded very well in the Brachyceras group at that time or earlier, 

 but have no successful experience in any other group. 



Several enemies attack waterlilies and work great havoc. In the 

 seed beds, algse may grow up and choke the little plants ; the use of less 

 manure and more sand in the pots is a preventive measure, and weak 

 Bordeaux mixture will kill the algae. After the first transplanting, a 

 damping-off fungus sometimes carries off numbers of seedlings ; the leaves 

 become transparent in ever-increasing areas until they are all gone. This 

 must be prevented by care in pricking off; if the plants are not wounded, 

 and are not weakened by the shock of moving, they will outstrip the fun- 

 gus. Snails, too, sometimes devour the leaves, or cut them off and leave 

 them floating on the tank ; pick out the offenders and throw them away. 

 The first floating leaves are often seriously weakened by swarms of 

 aphides. A strong spray from hose or syringe will wash them off, and a 

 few sun-fish or paradise fish will effectually prevent their return to the 

 leaves. 



As to enemies of mature plants, I can do no better than to quote 

 Mr. Tricker's summary from the Cyclopedia of American Horticulture 

 (1901, p. 1104) : 



Aphides are sometimes troublesome. The best remedy is their natural enemy, 

 the " lady bugs " or " lady birds." A colony of these voracious insects makes short 

 work of the aphides, as do also the lace-winged flies. An insect of recent acquaint- 

 ance with Nymphaeas is a leaf-miner, the larva of a small fly, which cuts channels 

 through the leaf in all directions. Sometimes only a few of these are in evidence, at 

 other times the leaves are fairly alive with them. The trouble is easily detected. The 

 marks suggest Japanese writing or the efforts of youthful artists. A simple and effec- 

 tive remedy is kerosene emulsion, applied with a fine spray at evening after the flow- 

 ers are closed. Another troublesome insect has its home in Florida, and has come 

 North to spend the summer in a favored clime. This is a leaf-cutter, Hydrocampa 

 proprialis. The larva cuts out pieces of the leaf and hides between two pieces, which 

 make a kind of tent. In this tent the larva moves about. At first it moves slowly, 

 but as it nears maturity the larva becomes ravenous and then eats the surface of the 



