bearing more regularly, in fact, than even the wild hazels
growing nearby. My comparisons have been made with wild hazels in both
Minnesota and Wisconsin and with European filberts.

I found the first point of similarity with the filbert is in the
involucre covering the nut. In the wild hazel, this folds against itself
to one side of the nut, while in the filbert it is about balanced and if
not already exposing a large part of the end of the nut, is easily
opened. The involucre of the Winkler hazel is formed much more like that
of the filbert than that of the hazel. In Corylus Americana this
involucre is usually thick, tough and watery, while in the filbert it is
thinner and drier, so that while a person may be deceived in the size of
a hazelnut still in its husk, he can easily tell that of a filbert. This
is also true of the Winkler whose involucre is fairly thick but outlines
the form of the enclosed nut. Another feature about the involucre of the
Winkler which classes it with the filberts rather than the hazels is in
its appearance and texture, which is smooth and velvety while that of
the hazel is hairy and wrinkled.

The staminate blooms of the Winkler hazel show similarity to those of
both filberts and hazels. Sometimes they appear in formation at the ends
of branches, much as those of the European filberts do, in overlapping
groups of three or four. Again, they may be found at regular intervals
at the axis of leaf stems very much as in the case of the American
hazel. The buds on the Winkler hazel are dull red which is also true of
those on the hybrid hazilberts, another indication of hybridity.

The initial growth of the embryo nut is very slow in the Winkler as it
is in the filbert, as contrasted with the very rapid development of the
native hazel embryo which matures in this latitude about one month ahead
of the Winklers and some filberts. Although Winkler nuts are shaped like
hazels and have the typically thick shells of hazelnuts, their size is
more that of a filbert usually three times as large as a native hazel.

During the years between 1942 and 1945 many new hybrids between filberts
and hazels were produced. Four wild varieties of hazels, which had
unusual characteristics such as tremendous bearing and large size nuts
and others having very early maturing or very thin shelled nuts were
used as the female parents in making the crosses. Pollen was obtained
from other parts of the U. S. or from filbert bus