226 ON PRESERVING NEWLY-COLLECTED FLOWERS. [AugUSt, 



flowers for nearly a fortnight without changing the water, which 

 continued bright and sparkling, studded with the air-bubbles 

 thrown off by the Algse. The quantity of gases thus exhaled by 

 the water- weeds supplied the nourishment required by the gathered 

 flowers, which inhaled them with avidity, and flourished with every 

 appearance of native vigour. 



Nor does it appear to signify what kinds of Algse are selected 

 for this purpose. My plates, for want of space, contained tufts 

 or fleeces of Lyngbya muralis, Vaucheria dichotoma and ccespi- 

 tosa, Zygnema of various species, Ulva bulbosa and crispa, Clado- 

 phora fracta and glomerata, besides several innominata. The Ba- 

 trachospermea, of which I had several species, and Draparnal- 

 dia plumosa, are too fragile to risk entanglement with the stems 

 of the flowering plants. The only essential condition seemed to 

 be that the Algse should be exposed to the light and influence of 

 the sun, so as to stimulate them to the production of the air- 

 bubbles, which purified the water while they nourished the ga- 

 thered flowers. 



I believe that in proper vessels (which the ingenuity of the bo- 

 tanist will suggest) gathered flowers and slips of plants might be 

 thus kept in health for a long time without once changing the 

 water. Among the Algse there is sure to be found a sufiiciency 

 of animal life to maintain the necessary balance. After the weeds 

 have been some little time in the water, many curious and beau- 

 tiful annelids and water insects will be observed in full acti^dty. 

 In one of my plates is a beautiful little spider, about the size of 

 the head of a pin, of a most brilliant scarlet above and black 

 beneath, whose rapid movements I am never tired of observing. 



If more animal life than that furnished by the weeds be con- 

 sidered necessary, the pretty little molluscs Succinea putris and 

 Ancylus fluviatilis will be found useful, as, though active in the 

 water, they make no attempts to leave it. This cannot be said of 

 the Limnead(B (fresh-water snails), which, from their rambling 

 propensities, are a perpetual trouble : every now and then they 

 may be heard to fall from the table, and, like the land snails, 

 may be traced by the shining track they leave behind them. But 

 for this propensity of wandering, the presence of these interesting 

 little creatures would decidedly add to the pleasure of the lover 

 of Nature, by the opportunity thus afforded of studying their 

 habits. 



