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natural effect is just the same as that of girdling the tree,
as far as the bark is so eaten.  If the whole circumference
is eaten round, the tree must die; if partially eaten, the
the tree will languish and become unthrifty for want of nourishment
in proportion to the extent of the wound. * * *
We have a right, till the contrary is proved or rendered
probable, to suppose that the worm does no more than we see.
If so, we may say without hesitation, that the 'yellows' is
not occasioned by the worm.  There are two facts which if
the worm does no more than eat the bark are decisive on this
point.  1. The worm has been committing its ravages upon our
trees for many years without any appearance of the 'yellows'.
They have been girdled trees so as to produce death, without
and of the phenomena peculiar to that disease.  2. Trees
that have never, as far as we know, been touched by the worm,
have died of the 'yellows'.  Of the two in my orchard which
had the disease in 1828, one only had been wounded by the
worm.  Of the fifteen which took the disease in 1830,
thirteen were free (and ever had been so) from any discoverable
attack of that animal.

"5. "Mr. Prince (<s>1.e.</s> * * * Supposes the disease
to be propagated by infection, by means of the pollen of a
diseased tree, carried by wind or insects to the blossoms of
        