NATURE IN MOTION. 45 



scatter the blessings of the vegetable world over the 

 nations of the world. Almost one-fourth of all plants 

 upon earth bear seeds that are provided with wings, para- 

 chutes, ^or other ^contrivances, by means of which they 

 may be carried on the wings of the wind to distant 

 regions. Every brook and every river, even a short-lived 

 rain, carry a thousand plants to remote countries. The 

 great ocean itself, on its mighty currents, bears fruits and 

 nuts from island to island, and every coral reef in the 

 South Sea is almost instantly covered with a rich, luxu- 

 riant vegetation. 



New plants appear thus constantly, where they were 

 formerly not found, whilst of the disappearance of ve- 

 getables there are but few isolated instances known. 

 Thus, Egyptian monuments have in their quaint and 

 well-preserved paintings, three kinds of sea-rose ; only two 

 of these are now met with in Egypt or the adjoining 

 countries; the third is not found there or anywhere over 

 the wide world. 



The most efficient agent employed by plants for their 

 journeys is man himself. History and science both teach 

 us that the heated air, which, coming from the poles and 

 rushing to the equator, there falls in with the great life- 

 artery of the globe, and in a constant, almost organic 

 current follows the apparent course of the sun from east 

 to west, gives us the direction in which all life and 

 motion proceeds upon earth. This great movement, no 

 doubt as old as the globe itself, and yet the last known 

 to man, is still going on ; and whilst history furnishes us 

 with a vast number of well authenticated facts, the pre- 



