80 Variation 
uniform strains without further selection, has, until a few years ago, 
been almost entirely lost sight of. Only a very few agriculturists 
have applied it: among these are Patrick Shirreff* in Scotland and 
Willet M. Hays? in Minnesota. Patrick Shirreff observed the fact, 
that in large fields of cereals, single plants may from time to time 
be found with larger ears, which justify the expectation of a far 
greater yield. In the course of about twenty-five years he isolated in 
this way two varieties of wheat and two of oats. He simply multiplied 
them as fast as possible, without any selection, and put them on the 
market. 
Hays was struck by the fact that the yield of wheat in Minnesota 
was far beneath that in the neighbouring States. The local varieties 
were Fife and Blue Stem. They gave him, on inspection, some better 
specimens, “phenomenal yielders” as he called them. These were 
simply isolated and propagated, and, after comparison with the 
parent-variety and with some other selected strains of less value, were 
judged to be of sufficient importance to be tested by cultivation 
all over the State of Minnesota. They have since almost supplanted 
the original types, at least in most parts of the State, with the result 
that the total yield of wheat in Minnesota is said to have been 
increased by about a million dollars yearly. 
Definite progress in: the method of single-ear sowing has, however, 
been made only recently. It had been foreshadowed by Patrick 
Shirreff, who after the production of the four varieties already 
mentioned, tried to carry out his work on a larger scale, by in- 
cluding numerous minor deviations from the main type. He found 
by doing so that the chances of obtaining a better form were 
sufficiently increased to justify the trial. But it was 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 Svaléf 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, 
1 Die Verbesserung der Getreide-Arten, translated by R. Hesse, Halle, 1880. 
2 Wheat, varieties, breeding, cultivation, Univ. Minnesota, Agricultural | Experiment 
Station, Bull. no. 62, 1899, 
