258 Seed- Scattering 



germinated after a voyage of more than 3,000 miles — 

 a distance greater than that which lies between Europe 

 and America. 



The question was, then, whether there were any way 

 in which they might float ; and it was found that 

 though ripe, freshly gathered hazel-nuts sank directly 

 they were put in water, they would float for as much 

 as ninety days, and then germinate, if they were first 

 dried. 



Now, in the natural state, seeds may often be dried 

 by exposure to sun and air before they are washed, or 

 blown, into the water ; and they would, some of them 

 at all events, be then perfectly well able to float. A 

 plant of asparagus, for example, floated nearly as long 

 as the nuts, after being dried, and its berries germi- 

 nated ; and asparagus, being a plant which grows wild 

 on the sea-coast, would have especially good opportu- 

 nities, therefore, of migrating. 



Drying does not answer the purpose with all plants, 

 however ; but out of ninety-four, upon which the expe- 

 riment was tried, eighteen floated more than twenty- 

 eight days, and some much longer, quite long enough, 

 in fact, to allow of their being carried from one con- 

 tinent to another. 



For Mr. Darwin's estimate of a mile an hour as the 

 rate at which ocean-currents travel, was a purposely 

 low one ; several of the Atlantic currents travel thirty- 

 three miles a day, and some as much as sixty miles a 

 day, so that any of these eighteen plants might have 

 been carried some hundreds of miles, and others from 

 three to five thousand, without their seeds being any 

 the worse for the voyage. 



Some seeds appear to have no means at all of getting 



