186 Mr. Knight’s Experiments and Observations 
But, in the inverted cutting, or tree, these vessels become in- 
verted ; and, if their organization be such as I have supposed it, 
a considerable part of that fluid, which naturally descends, will 
be carried upwards, and occasion the production of new wood, 
above, instead of below, the junction of the annual shoot with 
the older wood, as in the experiments I have described. The 
force of gravitation will, however, still be felt; and, by its agency, 
sufficient matter to form new roots may be conveyed to those 
parts of the inverted cutting, or tree, which are beneath the soil. 
Besides, if we suppose a variation to exist in the powers or 
organization of the vessels which carry the sap towards the 
root, we may also attribute, in a great measure, to this cause, 
the different forms which different species or varieties of trees 
assume ; for, if the fluid in these vessels be impelled with much 
force towards the roots, little matter will probably be deposited 
in the branches, which, in consequence, will be slender and 
feeble, as in the vine; and there is not any tree that has been 
the subject of my experiments, in which new wood accumulated 
so rapidly at the upper end of inverted plants. To an excess of 
this power, in the vessels of the bark, we may also ascribe the 
peculiar growth of what are called weeping trees ; for, by this 
power, the effects of gravitation will be, in a great degree, 
suspended ; and the pendant branch will continue healthy and 
vigorous, by retaining its due circulation. The perpendicular 
branch will, however, still possess some advantages ; for, in this, 
gravitation will act on the fluid descending from the leaves; 
and these will of course absorb from the atmosphere with in- 
creased activity. A greater quantity of matter will therefore 
enter, within any given portion of time, into vessels of the same 
capacity; and this increased quantity may frequently exceed 
