300 



WATCH OF FLORA. 



MRS. F. 



In proportion as the climate is colder, the expansion takes 

 place the later. Thus, a plant which would open at six 

 o'clock in the morning at Senegal, would only expand at 

 eight or nine in France, and at ten in Sweden; so that the 

 expansion is calculated to be an hour later for every ten de- 

 grees of latitude. Heat and light would therefore appear to 

 be the chief agents in the opening and closing of flowers; but 

 that they are not the only ones is evident, from some flowers 

 opening only at night, and others being also subjected to at- 

 mospheric influence. 



ESTHER. 



Such as the little scarlet pimpernel (Jlnagallis arvensis), or 

 the convolvuli, which close when it is going to rain. 



MRS. F. 



Or the Virginian sow thistle, which if it shuts its flowers 

 in the evening, we may be sure of a fine day; and if it opens 

 them, we may prognosticate that the next morning will be 

 rainy. Indeed, a number of flowers might be enumerated 

 which oifer parallel hygroscopic phenomena; and if they 

 were collected, we might form a barometer, as well as a 

 watch, of Flora, but here is the Table which I promised to 

 show you: 



WATCH OF FLORA. 



