"The recurrent daily phenomenon has not only been observed by the poets, but an explanation offered for it. It is the moonlight then that causes the opening of the lily, and the sunlight the movement of closure. Had the poet taken out a lantern in a dark night; he would have noticed that the lily opened at night in total absence of the moon; but a poet is not expected to carry a lantern and peep 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 moonlight, nor yet close to the sun." THE 'SLEEP' AND 'WAKING' OF JHINGA FLOWER The waking and sleeping of the water lily is by no means an isolated instance. My attention was first drawn to another remarkable floral display by the folk song which begins with: "Our day of work is over Like life's span, but an hour! For now behold the gold-starred fields Of opening 'Jhinga' flowers!" Since then I witness every afternoon a glorious transformation in my experimental garden at Sijbaria on the Ganges. The gardener has planted a large field with Jhinga (Luffa acutangula). The flowers when closed at day time are very inconspicuous, the lowest whorl of the sepals being dull green: in my afternoon walk I can hardly recognise the old familiar field, which is now covered with masses of flower in their golden glory. Here also the flowers remain open throughout the night; but they close early in the morning and the fairy field of cloth of gold vanishes suddenly. COMPLEXITY OF THE PROBLEM