74 KNAPP METHOD OF GROWING COTTON 



Cross Fertilization. When it is desired to 

 combine the good qualities of two varieties 

 in a single stock, this work can be best ac- 

 complished by cross fertilization. It is quite 

 probable that most of the varieties which have 

 been developed from single plants have really 

 originated by means of accidental crossing of 

 different varieties. 



While cross fertilization is the surest method 

 for the production of new varieties, it is largely 

 work in the dark, as plants resulting from the 

 crosses may inherit the weak qualities of both 

 parents without showing the good qualities 

 of either. It is often necessary to make a 

 hundred or more crosses before producing a 

 plant showing the desired combinations. Even 

 after a plant has been secured showing the 

 desired qualities the majority of its offspring 

 will not inherit these qualities. After the 

 cross is made and a plant of desired type 

 secured it is then necessary to practise care- 

 ful seed selection for a number of years before 

 there is much uniformity between the different 

 plants. 



While there is much variation between in- 

 dividual plants resulting from a single line 



