surviving the first winter, I built wooden shelters which completely
enclosed them, filling these shelters with forest leaves and protecting
them against mice with screen covers. No doubt this was a decided help;
at least all of these heartnuts lived for many years until the invasion
of the butternut curculio and the damage done by the yellow bellied sap
sucker bird caused me the loss of all except one variety, the Gellatly.
This variety I have perpetuated by re-grafting on other black walnut
stocks and by spraying and covering the limbs with screen to prevent the
sap sucker from working on it, still have it in the nursery and at my
home in St. Paul where a young tree on the boulevard bears each year.

I have found that heartnuts are difficult to propagate, the number of
successful grafts I have made being far below that of black walnuts on
black walnut stocks. The reason for this is not well understood any more
than is the fact, in my experience, that the Stabler walnut will graft
readily and the Ten Eyck persistently refuses to. A good feature that
these grafted trees do have, however, is their early productiveness. I
have seen them set nuts the second year after grafting and this has also
occurred in trees I have sold to others.

When a nut of J. sieboldiana cordiformis is planted, it does not
reliably reproduce itself in true type, sometimes reverting to that of
the ordinary Japanese walnut, which looks more like a butternut and has
a rather rough shell as distinguished from the smooth shell of the
heartnut. In hulling my heartnut crop for 1940, I noticed many deformed
nuts.

The season had been a prolific one for nut production of all kinds, and
I knew there had been a mixture of pollen in the air at the time these
nutlets were receptive (a mixture made up largely of pollen from black