326 WINGE, THE INTERACTION BETWEEN TWO CLOSELY LINKED LETHALS 


Spread Normal 

Oor og 


x K 123 35 meso 13000051 
x K 124 DE oa a5 244 
K 1202 ARE Sos 250 
K 205 220 20 1 1 025 
K 206 42 | 47 | 60 | 53 
K 207 53 | VEN EX 
x K 208 9 514,4 8 
j 250 | 237 | 265 | 264 


Found A 487 (23829 

Theoretically. . . 508 508 


\ 
It does not appear from table II that the F, Spread individuals 
(New Spread) produced by crossing Spread and the normal type 
has another genotypical constitution than the original Spread 
(which I call Old Spread in distinction from the new type), for 
just as is the case with the latter the former gives an offspring 
when mated to normal individuals, of which one half is Spread, 
the other half normal; but when crossed with Old Spread the 
difference is apparent, for while Old Spread X Old Spread gives 
nothing but Spread so long as no crossing-over takes place, New 
Spread x Old Spread in accordance with the theory gives 2 
Spread: 1 normal, as shown in table III. 
Ill. Spread (new type) x Spread (old type). 
Spr Vit Spr Vit 
spr Vit © spr vit 
Spr Vit |, Spr Vit | spr Vit | spr Vit 
Spr Vit ° spr vit Spr Vit * ! spr vit 
Spread Spread normal 
| (old type) | (new type) | (new type) 

Theoretically : 
1 




Phenotype : dies 

