DESCENT OF THE ROOTS. 107 



again began to grow, and continued to flourish till it 

 was blown over by the wind. Those who observed 

 the singular situation of this tree, and marked its very 

 unusual progress, have attempted to explain by what 

 law of nature, or by what perceptive power inherent 

 in the plant itself, the descent of its roots, so necessary 

 in this situation, was produced. 



Some have inferred that the young tree perceived the 

 store of food at the bottom of the wall, and like Israel 

 of old, sent its messengers to a distance, to avoid the 

 famine by which it was threatened. Others have refer- 

 red it to that general law of nature, by which all roots 

 descend towards the centre of the earth, until they 

 meet with resistance ; and those who have observed 

 the descent of the radical fibres of Hyacinths, when 

 growing in pure water, will be inclined to adopt the 

 latter opinion. But still they will admire that wonder- 

 ful provision, by which a Plane tree, on a high wall in 

 Galloway, would provide for its own security, as suc- 

 cessfully, as- if it had been blessed with an ordinary 

 share of human intelligence. And with respect to the 

 experiment of Wildenow, it has been justly observed, 

 that the Strawberry plant advanced towards the rich 

 soil in its neighbourhood, because in that direction, it 

 met with a better supply of nourishment, for the rad- 

 ical fibres thus situated, grew luxuriantly, while those 

 which remained in the sand, soon perished from the 

 want of sustenance. 



It seems almost unnecessary to observe, that roots 

 are situated beneath the surface of the ground, but to 

 this rule Parasitic plants furnish us with an exception. 

 They either derive their nourishment from the air, or 

 in the true spirit of prodigality, subsist on the resour- 

 ces of their neighbours, to which, in various ways they 



