Mr. Nicholas Longworth inquires: “Will the pit of the budded peach
produce the same fruit as the bud, or as the stock, or a mixture of
the two?” And he also says, “I have never fairly tested the question,
but my experience led me to believe that the budded pit produced the
same fruit as the original stock.”
So far as this question can be determined (independently of
experiment) upon the known laws of the vegetable kingdom, we say that
it will _not_ produce fruit like that of the original stock; nor will
it, on the other hand, with any certainty, reproduce the budded kind.
If the pit of a budded variety takes after the _stock_, we must very
much change our theory of the office of leaves, and perhaps of the
bark. At present, the received and orthodox teaching is, that the sap
from the root is crude and undigested until it has received in the
leaf a chemical change. Until then, the sap does not materially
influence the vegetable tissue, nor form new substance, or affect the
fruit. But _after_ its elaboration in the leaf, a returning current of
prepared sap (similar in its functions to arterial blood), sets
downward, distributing to every part of the vegetable economy the
properties required by each. The sap arising from the root, does not
touch the channel of fruit until it has been chemically changed; and
the difference exhibited in the fruit of one tree compared with
another, arises, primarily from the nature of the sap which it
receives; the sap receives its qualities by a digestion in the
leaf.[15] In all cases, then, we suppose the _leaf_ to determine the
nature of the fruit (and the root in no case, and the trunk in no
case), since the stem is, so far as sap is concerned, but a bundle of
canals for its passage—a mere highway for transmission—and not like
the leaf, a laboratory for its preparation![16]
We may be reminded that a _stock_, in point of fact, _does_ influence
the fruit. It is indisputable that pears are changed on quince roots.
The _Wilkinson_, grafted upon the quince, is smaller, more prolific,
higher flavored, and of a brighter red cheek than if grafted on the
pear. The Duchesse d’Angoulême is larger and better on the quince than
on its own roots. But what is _the_ influence in this case? When a
free-grower is put upon a slow-grower, the point of junction becomes a
point of comparative _obstruction_ to the return-sap. It is only a
wholesome process of _ringing, or decortication_. Lindley says:
“When pears are worked upon the wild species, apples upon crabs, and
peaches upon peaches, the scion is, in regard to fertility, exactly in
the same state as if it had not been grafted at all: while, on the
other hand, a great increase of fertility, is the result of grafting
pears upon quinces, peaches upon plums, apples upon the thorn, and the
like. In these cases, the food absorbed from the earth by the root of
the stock is communicated slowly.” And Manning adds: “No other
influence have we ever noticed exercised by the scion upon the stock.”
But if, after all, it can be shown by actual trial, that the pits of
budded peaches DO _go back to the fruit of the stock_, why we must
receive it, in spite of all theory; for, (and some would do well to
heed the maxim), facts must rule our theories, and not theories our
fact. But we may properly put any facts seeming to contravene the
received theory of the functions of plants in producing fruit, _upon
their oath_, and refuse them, unless they are unquestionable and
relevant.
Suppose a budded peach not to yield a fruit at all like the bud,
suppose it to resemble the fruit of the stock, it does not follow that
the _stock_ influenced the fruit to such a change. Mr. Longworth knows
how freely some peaches “sport,” and that all peaches may be made to
do it. If a Melacatune be budded upon a Red Rareripe, and the
Melacatune pit shows a fruit resembling the Red Rareripe, it must be
shown that the blossom had not been crossed by the busy offices of
flies, bees, etc., with the pollen of contiguous Red Rareripe-trees.
When a tree is even _solitary_, it does not follow that a change in
fruit which shall make it resemble the stock more than the graft,
results from the force _of the stock_ on the grafted fruit, for
seedlings of grafted fruit are, notoriously often, base and
degenerate; and the resemblance might be accidental, for seedlings of
different origin are often strikingly alike.
While we are aware of no facts which justify Mr. Longworth’s
suspicion, that the pits of budded varieties produce kinds like the
stock on which the bud was put, we have facts enough showing that
“budded pits” produce their own kind.
It may be added that _thoroughly_ ripe peaches are less inclined to
“sport” than those which are partially green.
[15] The fruit itself still further elaborates the sap, else
a peach would be as acrid as the juice of the peach leaf.
[16] Loudon (Encyclopædia of Gardening, p. 448), has the
following remarks:
“The bark is the medium in which the proper juices of the
plant, in their descent from the leaves, are finally
elaborated and brought to the state which is peculiar to the
species. From the bark these juices are communicated to the
medullary rays, to be by them deposited in the tissue of the
wood. The character of timber, therefore, depends chiefly
upon the influence of the bark: and hence, it is that the
wood formed above a graft never partakes, in the slightest
degree, of the nature of the wood below it. The bark, when
young and green, like the leaves, is supposed, like them, to
elaborate the sap, and hence may be considered as the
universal leaf of a plant.”
These views corroborate the reasoning above, although Loudon
extends the functions of the leaf to the _bark_. We have not
been able, in our limited range of books, to find any other
authority for this statement, respecting the “young and
green bark.”