646 PRACTICAL PROBLEMS 



Manifestly all the plants 

 on this centgener plot have 

 the same centgener num- 

 ber, but any promising 

 plant in the plot may be 

 given a " nursery number " 

 at any time, so that after 

 the system is well started 

 every plant has two num- 

 bers, its centgener number 



and its nursery number. 

 From these original records Z 

 three other sheets are made Q 

 up as a kind of ledger ac- 



three other sheets are made cr. 6 ^ 



*l \ 



count with this particular UJ 

 selection, extending per- [_ 



g 



** < 



a 



haps over several years. g 

 See forms 65, 67, and 68. 



The system seems some- 

 what complicated to a uj 

 novice, but it is easily and ^ 

 quickly mastered by those ^ 

 engaged in the work, and it ^ 

 is applied to all forms of < 

 breeding carried on at the | 

 Minnesota station. ^ 



The row system. This ^ > 



system is best illustrated 

 by its use at the Univer- 

 sity of Illinois, where it is 

 employed not only for corn 

 breeding but also for wheat, 

 oats, and other plants. The 

 same system has been 

 adopted by the Illinois j> 

 Seed Corn Breeders' Asso- 

 ciation, and is in use by all ^ 

 its members. 



