462 ON USEFUL AND BOOK I. 



5. The modes o f growth are very different in trees and shrubs. 

 Some send out their branches horizontally, as the oak; in 

 others, they tend upwards, as in the Huntingdon willow ; in 

 others* they fall, as in the lime, and the acacia. In some, they 

 incline obliquely, as in the Scotch fir ; in some, they recline, 

 and then rise up, as in the larch ; in others, they hang directly 

 down, as in the weeping ash and weeping willow. Some shrubs 

 creep along the ground, as the periwinkle ; others clasp them- 

 selves to trees, as the passion-flower ; others fix themselves to 

 buildings, as the ivy. Some trees in whatever way they may be 

 placed or pruned, constantly assume one principal stem, from 

 which all the branches proceed as rays from a centre, as in the 

 fir tribe; in others, the trunk divides itself into arms, which 

 send out branches irregularly, as the oak, &c. Some shrubs 

 have only a single stem, as the althaea; others constantly 

 spread along the ground, sending up more, as the hypericum. 



6. With respect to smells, some trees and shrubs have scarcely 

 any, as the evergreen oak and the platanus; others have a most 

 grateful fragrance, as the birch and the sweetbriar. Some have 

 a luscious smell, as the mezerion ; others a disagreeable smell, 

 as the elder ; and the smell of some is deleterious, as that of the 

 walnut and the artemisia. The fragrance of some is greatest 

 when the plant is in blossom, as the hawthorn ; in *s.ome, it is 

 ^confined entirely to the blossom, as the lilac; in others, it is 



