ON VEGETABLE ORGANOGRAPHY AND PHYSIOLOGY. 227 
Having gone over the contents of your very searching letter, we have 
to thank you for some very civil things you have stated in it, and to 
advise, if you ever again turn your mind to the subject, to surrender, 
if possible, those prepossessions which, from the tenor of your letter, 
appear to obstruct the entrance of whatever does not entirely accord 
with your first impressions, which, as the “ wise ones ” say, are ever 
the strongest. 
One thing we have overlooked, and that is, concerning what you say 
of the effects of mutilation. The first example is that of a space of the 
bark, without a twig or bud, insulated by having annular rings cut out 
above and below, remaining almost stationary, while the stem above 
and below the incisions is increased as usual. Secondly, that trees 
bleed freest in spring and autumn. Thirdly, that a shoot stripped of 
its leaves in the growing season, if it does not die, makes no addition to 
its substance. Fourthly, that a leaf and lateral shoot together taken 
from a vine-branch, tend to render the buds in their axil abortive in a 
succeeding year; and, lastly, that if a rhubarb plant be divested of too 
many of its leaves in this year, it will not develope so many in the 
next. Now it appears that these several well-known particulars are 
brought forward as proofs that all increase of the substance is from 
matter which descends, and prepared through the instrumentality 
of the leaves. Now we happen to believe just the contrary. We 
are compelled to believe, from the natural constitution of a plant, 
that it is destined to draw its nourishment chiefly from the ground, 
through the agency of the roots. This nourishment is naturally 
invited up by the transpiring action of the leaves, and the vacuums 
produced by swelling buds, lengthening shoots, and craving fruit. The 
sap is, moreover, elaborated in the various organs, and assimilated to 
the essential qualities by the action and influences of the atmosphere, 
and the current or currents of it are accelerated or retarded according 
as there are vents for its reception. If the outlets, therefore, be 
dammed up by constriction, or stopped or reduced by mutilation, either 
stagnation or diversion into other collateral channels, as happens to a 
shreded vine, must be the natural consequence. The providing and 
expending organs are naturally inclined to balance each other; and 
when such an equilibrium exists, healthy and regular development 
takes place in all plants in a natural state. But if art interferes to 
maim the bark, reduce the size or number of healthy leaves or shoots, 
or abridge the number or length of the roots, derangement follows, to a 
greater or less degree, according as the violence or mutilation is more 
or less extensive. 
This is the general law of vegetable development; and on an intimate 
