LINKAGE 67 



w a bi V m s r f b' ] 



YWABi VMS RFB' 



A number of females of this type have been made 

 up by Muller. The next formula shows the kinds of 

 eggs that were produced by one of these females and 

 the numbers of each kind that were produced. 



Non-crossovers: 

 ywabi vms rf b'-6. 

 Y W A Bi VMS R F B'- 8. 



Counts of over 600 offspring from females of the 

 same type have given similar results. The character- 

 istic method of interchange here demonstrated ma}^ 

 perhaps be better realized by contrasting the com- 

 binations just given with the following, which illus- 

 trate types of eggs found not to be produced by such 

 females • 



y W a Bi V m S r f B' 

 Y W a l)i V m s R f B' 



It is not supposed, however, that the per cent, of 



