I 231 ] 



By lopping trees, more nourishment is supplied 

 to the remaining parts ; for the sap flows laterally as 

 well as perpendicularly. The same reasons will ap- 

 ply to explain the increase of size of fruits by dimin- 

 ishing the number upon a tree. 



As plants are capable of amelioration by peculiar 

 methods of cultivation, and of having the natural term 

 of their duration extended ; so, in conformity to the 

 general law of change, they are rendered unhealthy 

 by being exposed to peculiar unfavourable circum- 

 stances, and liable to premature old age and decay. 



The plants of warm climates transported into 

 cold ones, or of cold ones transported into warm 

 ones, if not absolutely destroyed by the change of situ- 

 ation, are uniformly rendered unhealthy. 



Few of the tropical plants, as is well known, can 

 be raised in this country, except in hot houses. The 

 vine during the whole of our summer may be said to 

 be in a feeble state with regard to health , and its 

 fruit, except in very extraordinary cases, always con- 

 tains a superabundance of acid. The gigantic pine of 

 the north, when transported into the equatorial cli- 

 mates, becomes a degenerated dwarf; and a great 

 number of instances of the same kind might be 

 brought forward. 



Much has been written, and many very ingen- 

 ious remarks have been made by different philoso- 

 phers, upon what have been called the habits of plants. 

 Thus; in transplanting a tree, it dies or becomes un- 

 healthy, unless its position with respect to the sun is 

 the same as before. The seeds brought from warm 



