y has been sent, and we are in hopes that orders
for raspberry No. 4 can be filled in their entirety, though it may be
necessary to return money which has been sent for additional plants.

In this distribution all members will be treated exactly alike and
altogether in accordance with the conditions noted in connection with
the list of premiums as found on page six of the society folder and on
the inside front cover page of the magazine.

[Illustration: VIEW IN FRUIT-BREEDING GREENHOUSE, STATE COLLEGE,
BROOKINGS, S.D.

This is Prof. N. E. Hansen's laboratory, where he works out his problems
in cross-breeding. (See opposite page.)]

While it is not the intention to publish anything in this
magazine that is misleading or unreliable, yet it must be
remembered that the articles published herein recite the
experience and opinions of their writers, and this fact must
always be noted in estimating their practical value.

THE MINNESOTA HORTICULTURIST

Vol. 44 MAY, 1916 No. 5

What is Hardiness?

PROF. N. E. HANSEN, HORTICULTURIST, BROOKINGS, S.D.

By the term hardiness is understood the capacity to resist against any
special condition of environment. So in speaking of hardiness of the
plant it may mean hardiness as to either cold, heat, drouth, fungus or
insect trouble. In the present discussion hardiness against cold will be
considered mainly, since that is the most difficult problem we have to
meet in this horticultural field. It would be of great advantage could
we determine by examination of the plant its power to resist cold. If we
could determine by the looks of a new apple tree its power of resistance
to our test winters, it would save us many thousands of dollars and much
vexation of spirit. Some years ago the Iowa State Horticultural Society
made a determined and praiseworthy effort to determine hardiness by some
characteristic of the plant, especially in apple trees. A chemical test
of the sap of hardy and tender varieties was made. The palisade cells of
the leaf, and the cellular structure of the wood, were examined under
high powers of the microscope to determine some means by which a tender
variety could be distinguished from a hardy one, but no general rule or
conclusion could be formulated. In a general way nurserymen and
orchardists say that a variety that ripens its wood well in the fall
shows it by the twigs being sturdy and not easily bent, while twigs that
ar