en it does the nuts
fail to become more than half or two-thirds normal size by the time of
autumn frosts. The kernels are then quite undeveloped and the nuts
therefore worthless each year.

In another case, near Ithaca, New York, the Stabler walnut from Maryland
and the Ohio from Toledo, of the state after which it was named, all
appear to be congenially situated insofar as environment is concerned
until the nuts are actually harvested and cured. The nuts of each
variety appear normal when they drop from the trees, but during the
process of curing, the kernels wither up too badly to be marketable. The
Thomas from southeastern Pennsylvania is somewhat better able to adjust
itself to Ithaca conditions, but it is far from being a commercial
success in that region.

Kinds of Nuts

The kinds of nuts suitable for this northern zone naturally divide
themselves into three main groups, viz., native, foreign and hybrid. The
last might well be divided into three sub-groups, as native hybrids,
foreign hybrids, and hybrids between native and foreign species. It is
perhaps true that there should also be a fourth subgroup to which chance
hybrids should be assigned when there is uncertainty as to which of
these three others a given variety may belong.

The Native Group

Of these three main groups that of the native species is at present by
far the most important. It includes the black walnut, _Juglans nigra_;
the butternut, _J. cinerea_; the shagbark hickory, _Hicoria ovata_; the
sweet hickory, _H. ovalis_; the pignut hickory, _H. glabra_; the
American sweet chestnut, _Castanea dentata_; the American beech, _Fagus
americana_; and two species of native hazelnut, _Corylus americana_; and
the beaked hazelnut, _C. rostrata_.

Black Walnut

The black walnut is placed at the head of the native group because of
its great all round usefulness. Wherever it grows well its timber is of
leading value among all American species. It is a splendid ornamental
and the nuts are highly edible. The black walnut range does not extend
as far north as does that of the butternut, yet wherever it grows well
it is much more useful as a tree, and is successful under a greater
variety of conditions. It is probably a more dependable bearer and, upon
the average, the nuts yield a higher percentage of kernel. Many more
varieties of black walnut than of butternut have been brought to light
and more trees have been propagated. Enough varieties of promis