th show heavier
from the bottom buds of the branch than at the tip, and the pith is
usually solid at the bottom of the branch.

=Roots:= When the nut of the black walnut germinates in the soil the lobes
or cotyledons do not rise above the ground like the cotyledons of the
bean but remain in the nut shell under ground, and are broken off in the
growth of the seedling, the root going down and the stem rising above
the ground. Where the cotyledons are broken off, the so-called crown of
the walnut, two rough places appear, nearly opposite on the stem. In
these rough places, two groups of buds are formed, rarely three groups.

Cytological studies at Iowa State College have not shown why there are
not stem initials in the tap roots of the walnut. When the root is cut
off a foot underground, root initials develop but no stem initials. The
sensitivity of walnut leaf buds to water may have something to do with
it.

=Buds:= Buds of the walnut are in vertical groups of two or three in the
axils of the leaves. They have few scales. They appear on seedlings and
current year branches. Some have short stalks. If broken off they do not
usually grow back again. The second year, these buds usually drop off in
mid-season. In cutting off buds, unless the group of buds is taken out
as a chip, some may grow out again.

=Leaf arrangement:= There is a three rank arrangement of leaves in the
walnut, the ninth leaf coming in the same position as the first.
According to the work of Caesalpino, the buds should then rise in three
places at the crown. Only in rare cases does this occur in the black
walnut, although it is usual with the Persian walnut. If the nut is
planted deep this causes much suckering and a tendency to etiolate the
buds so they will stand water.

=Buds are sensitive:= Buds are sensitive to water, and storage material
must be fairly dry and cool. In two large boxes of scions received last
year from Germany, some 20 varieties of Persian walnut, all had dead
buds when received. They were packed in German peat. When buds are
covered with wax the wax must not be too hot or it will kill the buds.
In placing grafted walnuts in sphagnum or sand they should not stay wet
or the buds will die. Either unions must be above damp sand or sphagnum,
or the buds be protected by wax or adhesive.

=Sap:= In spring grafting there is an enormous flow of sap which will
sometimes tear the plates out of the pith. Grafts may be protected by
girdlin