t of future testing and
experience. In 1939 the question was again considered(2) and on the
basis of tests which had been made, changes were proposed which would
make the schedule more realistic. Since then many tests have been made
using the modified schedule. The purpose of this paper[A] is to give the
data secured in these tests and to consider again the value of the
schedule and possibilities of improvement.

[Footnote A: The authors are indebted to many persons for furnishing
samples for testing and for making duplicate tests. This cooperation is
gratefully acknowledged with thanks.]

Recently a number of papers have been published dealing with the
evaluation of black walnut varieties. In 1941 Kline and Chase(3)
compiled the available published data and additional tests made by the
Tennessee Valley Authority on nut weight and kernel percentage of black
walnut selections. Two hundred and twelve clones and 335 tests are
reported. As would be expected the samples of the same variety from
different localities show variation in weight per nut and in total per
cent kernel. For example, in 12 samples of the variety Ohio the weight
per nut varies from 14.8 grams to 18.7 and the per cent kernel from 16.6
to 32.9. Twenty-one tests of Thomas show variations in single nut weight
from 16.7 to 25.0 grams and in per cent kernel from 19.0 to 30.0. In
general the samples grown in the north were made up of smaller nuts with
less per cent kernel, indicating that the varieties were not suited to
that latitude.

In 1942 Kline(4) worked out a somewhat technical method of evaluating
walnut varieties on the basis of cash return per hour of labor spent in
cracking with a hand operated cracker. A formula is proposed in which
the variables of price and other factors may be substituted. The
approach is on a commercial basis and the method is not intended for use
in evaluating small samples. The paper represents many tests and
establishes or affirms by statistically treated data several points of
general interest in walnut testing, namely, (1) that a 25 nut sample is
large enough to show varietal or other differences of a gram in total
weight or 1 per cent of kernel weight, (2) that unless extreme accuracy
is desired, moisture content may be ignored in making tests of 25 nut
samples if the nuts have been hulled and air dried for about two months
and (3) that the mean weight per nut and per cent kernel of nuts from
the same tree may vary app