.

This gave, for a year or two, very promising results, but about the
third year the disease appeared to get over on to the margin, where it
had been cut. This led to the later discovery that the disease had been
running in the wood, as we had previously suspected. So the cutting out
of the bark alone is not sufficient. This year cutting has been done so
as to include a portion of the sap wood.

There is just one other topic which I want to allude to. That is in
regard to the immunity question. It has been found that this disease
attacks the common native chestnut, the chinquapin, the various
cultivated European chestnuts, but very rarely the Japanese. In regard
to this point. I hope that Doctor Morris will tell us something about
his experiments on the breeding of chestnuts with the idea of producing
a new and immune variety.

You will understand that I have just made an outline of this disease,
and I hope that, if there are any questions to be asked, you will make
them easy, so that I can answer them.

President Morris: This very interesting paper is now open for
discussion, and I hope that we can get some points which will allow us
to know how to control the disease. With the wind-borne spores that are
carried miles and miles by a single sharp gust of wind, this disease is
a difficult matter to control. We must, I believe, find some natural
enemies, if we can. I don't know where to look for these. I will have to
ask the mycologists what we may anticipate along the line of natural
enemies. I would like to ask if it is common for a weak species to
become a devastating species. Have we many parallels in the field of
mycology? The point relating to raising immune kinds is one for
discussion. Are we to raise immune chestnuts? The history of most
plants, I think, has been this, that where they have met their enemies
in their natural environment, the fittest survive; and it seems to me
that this is a case in which we perhaps have survival of the fittest in
North Asia; for the North Asian chestnuts certainly resist the disease
better than any others, but the chestnuts of southern Asia are quite
vulnerable to it. In my own orchards, I have twenty-six kinds of
chestnuts, and have followed them along, for the purpose of determining
which ones would resist the blight best. I cut out last year 5000 old
American chestnut trees on my property. There is not a tree in all that
part of Connecticut, the vicinity of Stamford, that