382 TENDENCY OF ROOTS. PART n. 



nonia is surrounded by a fringe of elongated spiral 

 vessels, the see 1 of the poppy has a reticulated surface, 

 and many have wings like* those of the ash tree, or down 

 like the thistle, that they may be dispersed by the wind. 

 The tendency of roots to strike downwards is so great, 

 that seeds right themselves whichever way they may 

 fall. 



