s Nilsson who discovered the almost inexhaustible
polymorphy of cereals and other agricultural crops and made it the
starting-point for a new and entirely trustworthy method of the highest
utility. By this means he has produced during the last fifteen years a
number of new and valuable races, which have already supplanted the old
types on numerous farms in Sweden and which are now being introduced on
a large scale into Germany and other European countries.

It is now twenty years since the station at Svalof was founded. During
the first period of its work, embracing about five years, selection was
practised on the principle which was then generally used in Germany. In
order to improve a race a sample of the best ears was carefully selected
from the best fields of the variety. These ears were considered as
representatives of the type under cultivation, and it was assumed that
by sowing their grains on a small plot a family could be obtained, which
could afterwards be improved by a continuous selection. Differences
between the collected ears were either not observed or disregarded. At
Svalof this method of selection was practised on a far larger scale than
on any German farm, and the result was, broadly speaking, the same.
This may be stated in the following words: improvement in a few cases,
failure in all the others. Some few varieties could be improved and
yielded excellent new types, some of which have since been introduced
into Swedish agriculture and are now prominent races in the southern
and middle parts of the country. But the station had definite aims, and
among them was the improvement of the Chevalier barley. This, in
Middle Sweden, is a fine brewer's barley, but liable to failure during
unfavourable summers on account of its slender stems. It was selected
with a view of giving it stiffer stems, but in spite of all the care and
work bestowed upon it no satisfactory result was obtained.

This experience, combined with a number of analogous failures, could
not fail to throw doubt upon the whole method. It was evident that good
results were only exceptions, and that in most cases the principle
was not one that could be relied upon. The exceptions might be due
to unknown causes, and not to the validity of the method; it became
therefore of much more interest to search for the causes than to
continue the work along these lines.

In the year 1892 a number of different varieties of cereals were
cultivated on a larg