430 



p. W. WHITING 



A type male paired with a sooty female produced 12 sooty, 

 6 males and 6 females, and 7 type, 4 males and 3 females. A 

 pair of these sooty produced 26 sooty, 10 males and 16 females, 

 and 9 type, 5 males and 4 females. A sooty male from the same 

 fraternity was paired with one of his type sisters. They pro- 

 duced 16 sooty and 20 type. 



A black male paired with a sooty female produced 6 sooty and 

 8 type showing dominance of gray over black and segregation 

 of sooty and type. 



A type male paired with a sooty female produced 11 sooty, 

 17 type, and 1 black, which is close to expectation as regards 

 sooty, but somewhat aberrant as regards black. 



Two cultures of heterozygous sooty produced 124 sooty and 

 40 type, very close to the expected 3 to 1 ratio. 



A sooty male paired with two sooty females produced 42 sooty. 



Soot}^ is then a character which segregates sharply from type 

 when once the complicating factors have been eliminated. 



E. Reversal of dominance of sooty by black 



A sooty male paired (125) ^yith a black female from the same 

 culture produced 129 sooty, 66 males (one with defective geni- 

 talia) and 63 females. The cross may be represented, SS.BB X 

 ss.bb. Six pairs of the sooty progeny, Ss.Bb. produced offspring 

 as shown in table 1. 



TABLE 1 



