166 THE MICROSCOPE AND ITS LESSONS. 



the currents take place, whose direction is pointed out by 

 the arrows. 



Does not the existence of a law invariably prove a 

 law-maker ? 



Would you really say, with the followers of Epicurus 

 and Lucretius, and their modern disciples, that the 

 Vallisneria spiralis had " acquired " its state of perfection 

 simply because it needed it? 



Our museums abound with specimens of what some 

 consider proofs of pre- Adamite man, or, at least, of pre- 

 historic humanity. Kudely carved implements in flint of 

 various forms have been found at such depths in the 

 earth that, without doubt, they are very ancient. They 

 must have been deposited for thousands of years in the 

 same place where they were first discovered ; but if they 

 afford evidence of one thing more than another, it is 

 evidence of mind, of intelligence and intellect, in their 

 form and fashion. But when we have such striking 

 instances as those in the Vallisneria, or the pitcher-plant, 

 or many other less attractive but equally humble plants, 

 some men are miserably content with putting it down to 

 " a law of nature," reminding us of Wordsworth's story of 

 the boy to whom 



" A primrose by a river's brim 

 A yellow primrose was to him, 

 And it was nothing more." 



How is it that some flowers close their petals while 

 rain is falling, which would spoil or wash away the honey 

 contained in their nectaries ? It is " a law of nature." 

 Why do other flowers close their beautiful eyes, and go to 

 sleep as punctually as the clock strikes the hours ? This, 

 too, is only " a law of nature." 



The flowering of plants takes place with striking 

 regularity, so much so that, by observing the exact time 



