97 



a/ % 



An examination of the preceding table will show that the common 

 wheat of the country, viz., Swedish Velvet Chaff, is taken as the basis of 

 comparison. 



The method of handling the products of artificial crossing is in principle, Method oj 

 much the same as that employed in ordinary line-breeding from old varieties, 

 as already explained. In ordinary line-breeding the great majority of mother 

 plants chosen are already constant and breed true. In the case of artificial 

 crossing-products a certain proportion of each generation is at first inconstant 

 and will divide further into constant and inconstant forms. In this case the 

 problem is to locate those individuals which seem to show the best com- 

 bination of desirable characters. This is accomplished substantially 

 as follows : 



All plants from each of the second generation plots are kept and the 

 seed from each sown in separate cultures. Field notes are taken on the 



Photo by L. H. N. 



FIG. XXI. Harvesting pedigree plots, 4th generation from the oat cross Gold Rain X 



Dala. 



plants produced (third generation) during the growing season and at harvest 

 a number of the best plots are chosen for further investigation. All plants 

 from each of these selected plots are taken up by the roots, bound into a 

 bundle, labelled and taken to the laboratory for still further examination 

 (See Fig. 21). The line of study here naturally varies somewhat, depending 

 upon the specific qualities sought for in a given crossing. This study together 

 with the field notes taken earlier in the season, permits a further reduction 

 to be made in the number of cultures, to a few of the most promising. Seed 

 from a large number of the best developed plants within each of these selected 

 cultures is then taken, each lot being given a number and in due time used to 

 plant other pedigree plots (fourth generation) . 



