TURNING OP FLOWERS TO THE LIGHT. £09 



it, especially the compound radiated ones, as 

 the Daisy,- Sun-flower, Marigold, &c. In 

 their forms Nature seems to have delighted 

 to imitate the radiant luminary to which they 

 are apparently dedicated, and in the absence 

 of whose beams many of them do not expand 

 their blossoms at all. The stately Annual 

 Sun-flower, Helianthus annum, displays this 

 phenomenon more conspicuously on account 

 of its size, but many of the tribe have greater 

 sensibility to light. Its stem is compressed 

 in some degree, to facilitate the movement of 

 the flower, which, after following the sun all 

 day, returns after sun-set to the east, by its 

 natural elasticity, to meet his beams in the 

 morning. Dr. Hales thought the heat of the 

 sun, by contracting the stem on one side, oc- 

 casioned the flower to incline that way ; but 

 if so, it would scarcely return completely at 

 night. There can be no doubt, from the ob- 

 servation of other similar flowers, that the 

 impression is made on their radiated florets, 

 which act as wings, and seem contrived chiefly 

 fof that purpose, being frequently destitute 

 of any other use. A great number of leaves 



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