230 SHADE-TREES IN TOWNS AND CITIES 



of the young trees. If, however, it is found desirable to 

 interplant young trees among large ones, which are to be 

 removed when the young trees grow up, then the branches 

 of the old trees should be so trimmed as to allow plenty of 

 sunlight to reach the small ones, and the roots of the neigh- 

 boring trees should be cut so that they will not interfere 

 with the new specimens. 



The period of the duration of life of city trees is much 

 less than that of the same species growing in the forest. 

 Their length of life depends upon the conditions of soil and 

 the care and culture bestowed upon them. 



