hybrids. My conclusion in regard to the effect of frost is that the
reaction of the Winkler hazel is very similar to that of the wild hazel
in color but exceeding it in beauty since its leaves do not drop as soon
after coloring. At this time, the leaves had not changed color on the
imported European plants, the Gellatly filberts from British Columbia or
the White Aveline type. They had turned only slightly on the Jones
hybrid. I think an accurate idea of the general hardiness of a plant is
indicated by the effect of frost and by early dropping of leaves, using
the sturdy wild hazel as the limit of hardiness and assuming that its
hardiness is shown by both degree of coloration and early dropping of
leaves.

In noting the action of frost on the Winkler hazel, I have mentioned
that it was more like that on the American hazel than on the European
filberts. The Winkler has always been considered a native woodland
hazel, but, although it does show several similarities to Corylus
Americana, I have also noticed certain qualities which definitely
suggest some filbert heritage. I have based my theory on a study of the
Winkler hazels which have been bearing annually at my farm for six
years, 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