MISCELLANEOUS VEGETABLE PHENOMEXA. 77 



by the touch, or by some unobserved force. AVe know 

 of no satisfactory theory to account for these demonstra- 

 tions. 



197. Linnaeus formed what he called a floral time-piece. 

 It was made of those flowers which open and close their 

 petals under atmospheric influence. Each hour was repre- 

 sented by a flower that expanded or shut up at that par- 

 ticular time. 



198. We have many flowers in our gardens that are thus 

 affected. The portulaca opens at sunrise and closes at 

 12 M. ; the marvel of Peru at 4 o'clock p.m.; the niglit- 

 jasmine at 8 p.m., and is deliciously fragrant until sun- 

 rise, when it closes and is entirely scentless. The night- 

 blooming cereus is another well-known night-bloomer. 



199. De Candolle, noting the time that flowers bloom in 

 Paris, arranged a floral clock, which you can take a hint 

 from and arrange one of Southwestern flowers. We have 

 a number of those that you will find in this " clock." 

 Here is the list, and their hours of expanding : 



Between 3 and 4 a.m. Bindweed of the hedgerows. 

 At 5 A.M. Naked-stalked poppy and most of the cicho- 

 i'acae. 



Between 5 and 6 a.m. Nipplewort and Day-lily. 



At 6 A.M. Many of the Solanaceae (nightshade family). 



Between 6 and 7 a.m. Snow-thistle and spurry. 



At 7 A.M. Water-lilies and lettuces. 



At 7 and 8 a.m. Venus' looking-glass. 



At 8 A.M. Wild pimpernel. 



At 9 A.M. Wild marigold. 



At 9 to 10 A.M. Ice plant. 



At 11 A.M. Purslain, star of Bethlehem. 



At 12 M. Most of the mesembryanthemum family. 



197. What did Linraeus form from a knowledge of the atmospheric effects upon 

 the expansion of flowers ? 



198. What flowers in onr gardens are thus afiected ? 



199. What did De Candolle arrange with flowers ? 



