188 



P0PULUS. 



quently reached a height of seventy or eighty feet, with 

 a diameter of three or four feet.* In dry soils the Aspen 

 never reaches a great size, though it lives many years, and 

 the wood is of good quality. 



It is easily propagated by the suckers, which are thrown 

 up in great abundance, as well as by the cuttings of the 

 roots, which succeed better than those taken from the 

 branches of the tree. Young seedlings are also abundant 

 in all woods where it grows, and these are perhaps pre- 

 ferable to plants raised by the other methods Ave have 

 named. 



The leaves are eaten by the caterpillars of many noc- 

 turnal Lepidoptera, as by that of Cerura vinula, Noto- 

 donta ziczac, &c, and by many of the Ohrysomelidee, 

 among which Phaedon vitulina, is sometimes very nu- 

 merous. 



The red warty-looking ex- 

 crescences upon the leaves 

 and leaf-stalks are produced 

 by wounds inflicted by the 

 ovipositor of a tipula which 

 selects these parts as depo- 

 sitories for its ego-s. 



In some countries curious 

 superstitions existed, and in- 

 deed still exist, respecting 

 the Aspen, originating from 

 the constant tremulous mo- 

 tion of the leaves ; thus, by 

 the Highlanders it is sup- 

 posed to be the wood of 



* See the statistics of the Aspen in Loudon's "Arboretum Britannicum.*' 



