[ 30 j 



are, many of them, provided with a light dowri^ 

 by which they are enabled, with the help of 

 the wind, to rife to great heights, and fpread 

 themfelves very wide to propagate their fpecies 

 in diflant lands. The fun, by its annual vifits 

 to the northern and fouthern tropics, alternate- 

 ly gives a6lion and reft to vegetation. The 

 floods, which in many countries fall at certain 

 feafons from the mountains, cover the plains, 

 and enrich the foil by the fediment of their wa- 

 ters. The winter's froPcs alfo, by expanding the 

 moifture contained in the earth, loofen and 

 break the clods, fo as to make them give way 

 to the fpreading roots of vegetables : fwine, 

 moles, and fome other animals, root up and 

 loofen the earth, and fit it to receive the feeds 

 of plants. 



The Rev. Mr. Robinfon, reftor of Oufoy in 

 Cumberland, in his Natural Hiftory of Weft- 

 moreiand and Cumberland, part II. page 97, 

 fays, that birds are natural planters of all 



forts of wood and trees : they diffeminate the 

 " kernels upon the earth, which, like nurferies, 



brings them forth till they grow up to their 



natural 



