THE SLEEP OF PLANTS 195 



THE NIGHT-WATCH OF NYMPHAEA 



The poets have forestalled the men of science. Why does the 

 water-lily Nymphaea keep awake all night long and close her 

 petals during the day ? Because the water-lily is the lover of 

 the Moon, and like the human soul expanding at the touch of 

 the Beloved, the lily opens out her heart at the touch of the 

 moon-beam, and keeps watch all night long ; she shrinks 

 affrighted by the rude touch of the Sun, and closes her petals 

 during the day. The outer floral leaves of the lily are green, 

 and in the day-time the closed flowers are hardly distinguishable 

 from the broad green leaves which float on the water. The 

 scene is transformed in the evening as if by magic, and myriads 

 of glistening white flowers cover the dark water. The recurrent 

 daily phenomenon has not only been observed by the poets, but 

 an explanation offered for it. It is the moon-light then that causes 

 the opening of the lily, and the sun-light the movement of 

 closure. Had the poet taken out a lantern in a dark night, 

 he would have noticed that the lily opened its petals at night 

 in total absence of the moon ; but a poet is not expected to 

 carry a lantern and peer out in the dark ; that inordinate 

 curiosity is characteristic only of the man of science. Again 

 the lily does not close with the appearance of the sun ; for the 

 flower often remains awake up to eleven in the forenoon. A 

 French dictionary maker saw Cuvier the zoologist about the 

 definition of the crab as ' a little red fish which walks backwards.' 

 ' Admirable ! ' said Cuvier. ' But the crab is not necessarily 

 little nor is it red till boiled ; it is not a fish, and it cannot walk 

 backwards ; but with these exceptions your definition is perfect.' 

 And so also with the poet's description of the movement of the 

 lily, which does not open to moon-light nor yet close to the sun. 



Nor has the scientific explanation hitherto offered proved 

 more satisfactory. The eminent plant-physiologist Pfeffer 

 regarded the ' sleep and waking movements ' to be due to 

 the recurring action of light and darkness, of sunrise and 

 sunset. The opening and closing of the water-lily has, 

 however, little or no connection with the rising or setting 

 of the sun ; the opening could not be due to setting sun 

 for the flower remains open in light up to about n o'clock 

 in the morning ; neither could it be due to the rising sun, 



