ELASTICITV OF LIGNIFIED TISSUES. 221 



young shool-axes, and likewise younger portions of root-fibres do, as a matter of 

 fact, so behave, is most easily observed thus : it is possible to give to them with the 

 finger almost any chosen curvature, which they then maintain for a long time, until 

 further changes take place through growth. The shaking of the objects, employed 

 by Hofmeister, may be better replaced by several blows given with a rod, applied 

 on one side of the older lower portions of the shoot. The free apex is thus made 

 to vibrate violently, and the apex in part maintains the strong curvature, so 

 that on coming to rest it hangs down. It is obvious that the powerful vibrations 

 given to slender flower stems by the wind in spring must call forth similar pheno- 

 mena; and upon this depends, at least in part, the unpleasant aspect of a garden 

 in a strong wind. 



