284 Mr. Knight’s Account of some Experiments 
parent tree, very feeble powers alone are wanted in the returning 
system. No power at’ ail had been fatal ; and powers sufficiently 
strong wholly to counteract the effects of gravitation, had pro- 
bably been in a high degree destructive. And it appears to 
me by no means improbable, that the formation of blossoms 
may, in many instances, arise from the diminished action of the 
returning system in the horizontal or pendent branch. 
I have long been disposed to believe the ascending fluids in 
the alburnum and central vessels, wherever found, to be every- 
where the same ; and that the leaf-stalk, the tendril of the vine, 
the fruit-stalk, and the succulent point of the annual shoot, might 
in some measure be substituted for each other ; and experiment 
has proved my conjecture, in many instances, to be well founded. 
Leaves succeeded, and continued to perform their office, when 
grafted on the fruit-stalk, the tendril, and succulent shoot, of the 
vine ; and the leaf-stalk, the tendril, and the fruit-stalk, alike 
supplied a branch grafted upon them with nourishment. But I 
did not succeed in grafting a fruit-stalk of the vine on the leaf- 
stalk, the tendril, or succulent shoot. My ill success, however, 
I here attribute solely to want of proper management ; and I 
have little doubt of succeeding in future. 
The young shoots of the vine, when grafted on the leaf-stalk, 
often grew to the length of nine or ten feet; and the leaf-stalk itself, 
to some distance below its juncture with the graft, was found, 
in the autumn, to contain a considerable portion of wood, in 
every respect similar to the alburnum in other parts of the tree. 
The formation of alburnum in the leaf-stalk, seemed to 
point out to me the means of ascertaining the manner in which 
it is generated in other instances ; and to that point my attention 
was in consequence attracted. Having grafted a great many 
