
          254

summer that twig grew to the length of five feet, and to the
size of a broom handle, with deep green leaves and every mark
of most perfect health.  The branches that sprung from the
headed trunk were severely affected by the 'yellows'."

[Compare Mr. Green's Delaware Orchard in 1887.]
See Field Notes & map.

Facts favoring.--"That the disease should first appear 
in the neighborhood of Philadelphia and thence gradually
spread in all directions, is one.  My own observations may
furnish some others.  I have traced the disease from a single
tree, in 1825, surrounded at that time for a mile with entire
health, till garden after garden, within the extending circle
had become wholly despoiled of those precious fruit trees. In
my own orchard, the two trees of 1828 stood within a rod of
each other; of the six in 1829, five were within a circle of
four rods diameter; of the fifteen of 1830, fourteen were
within a circle of four rods diameter."  But he adds: "I
cannot, upon that theory, well account for a circumstance very
often observable--a healthy tree standing two or three years,
and blossoming every spring, within a rod of a large diseased
tree, and yet continuing uninfected, while every other tree
for rods around takes the disease and dies.
[I observed a similar
case in one of Dr.
Maywell's orchards. Only 
the healthy tree was surrounded
by many diseased ones.]
        