1^0 STUDIES OF NATTTRE. 



which they are intended ; it is this, The duration 

 of their exiftence is regulated by the quantity of 

 heat which it is their deftination to collect. The 

 hotter it is, the fhorter is their duration. They 

 almoft all drop off as foon as the plant is fecun- 

 dated. 



But if Nature withdraws the greater! number of 

 flowers from the too violent action of the Sun, fhe 

 deftines others to appear in all the luftre of his 

 rays, without fuftainingthe leaft injury from them. 

 On the firft fhe beftows dufky reflectors, or fuch 

 as can clofe themfelves as occafion requires ; (he 

 provides others with parafols. Such is the crown- 

 imperial, whofe flowers, like a bell inverted, grow 

 under the (hade of a tuft of leaves. The chryfan- 

 themum-peruvianum, or to employ a better- known 

 term, the turnfol, which turns continually toward 

 the Sun, covers itfelf, like Peru, the country from 

 which it comes, with dewy clouds, which cool and 

 refrefli it's flowers, during the moil violent heat 

 of the day. The white flower of the lychnis, 

 which blows in our fields, in Summer, and pre- 

 fents, at a diftance, the refemblance of a Maltefe- 

 crofs, has a fpecies of contraction, or narrow col- 

 lar, placed at it's centre, fo that it's large fhining 

 petals turned back outwardly, do not act upon it's 

 flamina. The white narciffus has, in like manner, 

 a fmall tunnel. But Nature ftands in no need to 



create 



