at the Norris meeting of the Northern Nut Growers
Association. At that time the wood photographed in figure 1 was shown.

In the literature somewhat conflicting reports are found as to whether
or not curliness will show up early in the growth of a tree or late.
Apparently it was possible to trace curly grain into the twigs a few
years old in the original Lamb walnut (unpublished letters). Various
statements, however, indicate that curliness may not develop until the
trees are 20 years old or more. It would seem that with the propagation
and introduction of the Lamb walnut in 1926-27 and distribution soon
thereafter it ought to be possible to locate and examine these trees
which are now more than 20 years old.

[Illustration: Fig. 4. Slightly enlarged photograph of black walnut with
straight grain in the wood (light-colored area) and also in the bark
(dark-colored area). U. S. Forest Service Forest Products Laboratory
Photo.]

In the various literature and other material available on the subject of
birdseye and curliness, it appears that the birdseye grain is different
in its origin from curliness although both may be related to the
functioning of the cambium and definitely seem to be related to slow
growth. (Ref. 8)

[Illustration: Fig. 5. Slightly enlarged photograph of black walnut with
curly grain in the wood (light-colored area, upper left) and also in the
bark (dark-colored area). U. S. Forest Service Forest Products
Laboratory Photo.]

Curliness is reported in other kinds of trees. Curly grained white
poplar has been propagated from hybrid trees by growing cuttings of
shoots from the roots of the curly trees (Ref. 9). In Sweden it has been
possible to grow figured birch, much of which has the curly type grain.
In birch, seedling strains producing curly grain have been developed and
are being grown. It is of interest to note that with these birches, the
trees with curly grain grow only about half as fast as the normal trees
and have to be staked during their early growth years in order to make
straight trunks or to stand erect (Ref. 4).

The original Lamb walnut tree was curly throughout. Other trees,
particularly maples and birches may be curly only in part of their
trunks and sometimes only in restricted segments. Trees frequently have
curly grain at the base where the trunk joins the roots but not
elsewhere. Such curliness may be related to the shortening of the curve
where the root joins the trunk, thus