80 Variatioji 



iiuiform 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 

 Shirrefl", 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 

 agi'icultural 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 

 cars were considered as representatives of the type under cultivation, 



' Die Verbesserung der Getreide-Arten, translated by R. Hesse, Halle, 1880. 

 ' Wheat, varieties, breeding, cultivation, Univ. Minnesota, Agricultural Experiment 

 Station, Bull. no. G2, 1809. 



