294 GENETICS IN RELATION TO AGRICULTURE 



adopted a modified form of line selection in the improvement of rye, 

 which is also naturally cross-fertilized. 



Timothy breeding was undertaken by the New York (Cornell) Experi- 

 ment Station, under the direction of Hunt, Gilmore and others in 1903.' 

 To begin with, samples of seed were secured from 22 states and 11 foreign 

 countries. Although it had been long cultivated in certain parts of 

 Europe, there were no distinct varieties of this species of grass (Phleum 

 pratense) because it is normally cross-fertilized. Many interesting 

 variations were found among the plants grown from the various samples, 

 some of them being of great commercial value. After several years of 

 experimental work 17 new sorts were selected as most promising. These 

 had been increased vegetatively by division and subjected to progeny 

 tests with both cross-pollinated and self-pollinated seed. In two years 

 tests the 17 selections gave an average increased yield of 36% per cent, 

 above ordinary timothy. If such an increase in production of timothy 

 could be extended throughout the country, it would, according to Webber, 

 add over $90,000,000 to the value of the annual hay crop. 



Hybridization. The third general method of plant breeding in the 

 light of genetical science holds great promise of future possibilities. 

 In spite of Knight's early demonstration of the value of varietal crosses in 

 breeding, this method did not come into general use until the latter part 

 of the nineteenth century. According to Darbishire, another English 

 horticulturist, John Goss, made some of the identical crosses used by 

 Mendel, and noted the phenomena of dominance in Fi and recombination 

 in Fz, but failed to grasp the significance of the facts he observed. Accord- 

 ing to Munson, it was the horticulturist, A. J. Downing, who in 1836 

 first called the attention of American breeders to the possibilities in 

 hybridization. After his success with strawberries, Hovey, in 1844, 

 definitely championed the cause. The achievements of Hovey, Downing 

 and others soon led to the general adoption of cross-fertilization as a 

 method of breeding. In their efforts to secure varieties having certain 

 combinations of desirable characters, the crossing of varieties of small 

 grains was employed to advantage by Rimpan, Blount, Pringle, Hays, 

 Nilsson and others in later years. The remarkable Marquis wheat 

 which has proved so valuable in the northern wheat regions is a hybrid 

 according to Carleton which was probably made by A. P. Saunders at 

 the Agassiz (British Columbia) Experiment Farm in 1892. The applica- 

 tion of this method in the production of disease resistant commercial 

 strains has been attempted. R. H. Biffin began his study of wheat breed- 

 ing in 1909 in the service of the National Association of British and Irish 

 Millers. The demand was for a beardless, rust-resistant variety of high 

 yielding power and good milling quality. Not being able to discover any 

 single variety which combined all these characters, Biffin attacked the 

 problem from the Mendelian standpoint and has attempted to secure the 



