
          255

"Some circumstances encourage the suspicion, that the
disease is caused by a poison infused into the circulation,
through a branch of the tree, by some unknown insect.  If
such an insect had first appeared about the year 1797, in the
neighborhood of Philadelphia, and the successive generations
had colonized the country in all directions, by progressive
stages, it would account for the gradual spread of the 'yellows',
from that desired [diseased?] center, and for most of the phenomena
attending its dessemination.  The effects of the disease on
the suffering [trees?] are such, I think, as we might expect from 
poison--a debility or prostration of the vital energy,
particularly in the leaf."

"All early travelers in, and writers about Maryland,
have noted the fact that even before the first generation of
settlers had passed, the country was thickly planted with
orchards of apple and peach trees, which seemed to grow in
the most flourishing way.

"It is certainly remarkable that within twenty-two years
after the landing at St. Mary's [1634] orchards should have
become a noticeable and even conspicuous feature in the landscape;
but the evidence of the fact is conclusive: Probably
        