228 FARM GRASSES OF THE UNITED STATES 
plant breeder in recent years. Breeders have pursued 
two distinct courses with this crop. One set of breed- 
ers has been producing new varieties by crossing old 
ones. ‘Thus far there has not been a great deal accom- 
plished in this direction. It is only about three years 
since we first learned how to handle the apparently 
variable progeny of such across. A few varities have 
been produced that possess special qualities of more or 
less value. Now that we know how to get all the pos- 
sible new varieties out of a cross, and can even tell in 
advance what most of these varieties will be like, much 
more ought to be accomplished in this line of plant 
improvement. 
The other line of work with wheat has consisted in 
a careful study of a large number of individual plants 
in order to be able to save seed from the best. Prof. 
W. M. Hayes, of the Minnesota station, has done some 
excellent work of this kind, and has produced pedi- 
greed strains of some of the standard varieties of that 
section that considerably outyield the original varieties. 
Very little work of this kind has been undertaken 
with the standard hay and pasture grasses, but enough 
has been done to show valuable results. It has been 
shown that, in the crops that have been carefully 
studied, each kind of grass, as ordinarily sown by the 
farmer, consists in reality of a number of more or less 
distinct varieties mixed together. With the usual 
methods of securing grass-seed there is no opportunity 
to separate these varieties. In order to accomplish 
this, a careful study of the crop must be made until 
the grower is able to recognize the varieties of which 
it consists. This has been done in a few cases. 
