THE VEGETABLE KINGDOM. 429 



the results. In this way he noticed that a great number of 

 plants assume a particular attitude when they give them- 

 selves up to sleep : this is due to their need of repose, which, 

 as in most animals, coincides with the want of light. 



In certain families of the vegetable kingdom the plants 

 are even so transformed during their sleep that they are 

 not recognizable. The aspect of a forest or a savanna is 

 sometimes absolutely changed by it. Many bring their 

 boughs nearer to the stem, and apply their leaves one to 

 the other, so as to be a mutual protection against the cold. 

 Whoever has seen a sensitive plant during the night, with 

 its boughs drooping, and, as it were, overpowered by fatigue, 

 with its leaflets folded together like eyelids which close, 

 will admit that at such times it rests and sleeps. 



The phenomenon we are speaking of is seen in a much 

 more striking form in hotter countries. Humboldt, while 

 traversing the banks of the Magdalena, observed that 

 there plants awake much later than in less torrid countries, 

 as if vegetation in these climates shared in the indolence 

 which is observable in all the peoples scattered beneath the 

 equator. 



Many flowers close every evening in order to give them- 

 selves up peacefully to repose. There are some, such as 

 certain bind -weeds, which are very lazy, falling asleep long 

 before sunset, and only rousing up very late each morning, 

 when the sun darts his rays upon them. 



In the evening, if we view a meadow in which these im- 

 pressible flowers abound, its mournful aspect renders it un- 

 recognizable. In full midday, when it is enamelled with 

 all these open corollas, it seems a mass of verdure filled 



