260 (ECONOMY OF AQUATIC PLANTS. 



Gardeners foimcrly attempted to assist Nature by strip- 

 ping oflfthe barren flowers of Melons and Cucumbers, 

 which, having no germcn, they found could not come to 

 fruit, and were, therefore, as they supposed, an unneces- 

 sary encumbrance to the constitution of the parent plant. 

 But finding they thus obtained no fruit at all, they soon 

 learned the wiser practice of admitting air as often as 

 possible to the flowering plants, for the purpose of 

 blowing the pollen from one blossom to the other, and 

 even to gather the barren kind and place it over that 

 destined to bear fruit. 



The ceconomy of various aquatic plants throws great 

 light upon the subject before us. Different species of 

 Potamogeton, Engl. Bot. t. 168, 297, 376, &c., Ruppia 

 maritima, t. 136, and others, float entirely under water^ 

 often at some considerable depth, till the flowering season 

 arrives, when they rise near the surface, and throw up 

 their flowering spikes above it, sinking afterwards to ri- 

 pen and sow their seeds at the bottom. Nymphcea alba^t. 

 160, is very truly described by Linnaeus in his Flo7-aSue- 

 cica, -ds cIosin^^ its flowers in the afternoon and laying them 

 down upon the surface of the water till morning, when it 

 raises and expands them, often, in a bright day, to seve- 

 ral inches above the water. To tliis I can speak from 

 my own knowledge, and it is confirmed by the history 

 given by Theophrastus of his Lotus, which, according 

 to ail appearance, is the Nymph^^a Lotus of Linnaeus. 

 " This," says he, " as well as the Cyamus^, bears its 

 fruit in a head. The flower is white, consisting of 



* Exot. Lot. r, 31, 32. 



