3E£Db. 213 



In this way the plants of Germany find access to 

 Sweden, and those of Spain and France are scattered 

 over the shores of England. 



In these cases the difference of climate is not so 

 great as to prevent the growth of seeds which have 

 thus emigrated from their native country. On the 

 banks of the Connecticut we frequently meet with 

 plants which probably descended with its current from 

 the mountains among which it takes its rise ; plants 

 whose seeds ripened in Canada, and emigrated to a 

 more temperate climate. 



Winds also contribute to the dissemination of seeds. 

 We have seen how well many of them are adapted to 

 expose a large surface to its action, and we have often 

 observed them sailing through the air, in pursuit of a 

 new and distant home. It is scarcely necessary to 

 refer to the winged capsules of the Maple and the 

 Ash, which, in connexion with the seeds are pro- 

 pelled by the wind to a distance from their respective 

 trees. Nor is it necessary to say how effectually the 

 same object is secured by the winged seeds of the 

 Catalpa and Pine, which, in a similar way are elevated 

 and propelled through the air. 



Some seeds, like those of the Staphylea, are enclos- 

 ed in an inflated calyx, more resembling a balloon than 

 a sail, but equally effectual in diffusing over the globe 

 the seeds which they enclose. But the feathery 

 crown which invests the seeds of Compound flowers 

 affords a more beautiful specimen of mechanism than 

 any of these, and it is brought into operation through 

 the agency of dry air at the very moment best suited 

 for their dispersion. Aided by this, the Erigeron of 

 Canada has travelled from America to Europe, and 

 thence it has been diffused over the eastern continent. 



