the Direction of the Growth of Roots. 219 
granted, but because it is insufficient to explain the preceding 
phenomena, unless seedling plants be admitted to possess 
more extensive intellectual powers, than are given to the off- 
spring of the most acute animal. A young wild-duck or par- 
tridge, when it first sees the insect upon which nature intends 
it to feed, instinctively pursues and catches it ; but nature has 
given to the young bird an appropriate organization. The 
plant, on the contrary, if it could feel and perceive the objects 
of its wants, and will the possession of them, has still to con- 
trive and form the organ by which these are to be approached. 
The writers who have contended for the existence of sensa- 
tion in plants, appear to have been sensible of the preceding 
and other obstacles, and have all betrayed the weakness of 
their hypothesis, in adducing a few facts only which are fa- 
vourable to it, and waving wholly the investigation of all 
others. 
In the description of the preceding experiments, I fear that 
I have been tediously minute ; but, as I have selected a few 
facts only from a great number, which I could have adduced, 
I was anxious to give as accurate and distinct a view of those 
I stated, as possible. 
I am, dear Sir, 
with great respect, 
sincerely yours, 
THO. AND. KNIGHT. 
Downton, Jan. 15, 1811. 
Ff 2 
