GENETIC STUDIES ON FLOUR-MOTH 427 



1 . Free segregation of cleft and black. The Fa generation from 

 (105) consisted of 204 type, 58 black, 36 cleft, and 15 black cleft. 

 There are 240 gray to 73 black, the expectation being 234 to 78. 

 There is thus no appreciable deficiency of black. There are 262 

 normal to 51 cleft, the expectation being 234 to 78. There is 

 thus deficiency of cleft. Among the normal there are 204 gray 

 to 58 black, the expectation being 196.5 to 65.5. Among the 

 cleft there are 36 gray to 15 black, the expectation being 38.25 

 to 12.75. The deviation from expectation is not enough to 

 indicate linkage. 



The F2 generation from (109) consisted of 599 type, 309 males 

 and 290 females; 190 black, 95 males and 95 females; 87 cleft, 41 

 males and 46 females, and 27 black cleft, 12 males and 15 females. 

 The summary shows 686 gray to 217 black and 789 normal to 

 114 cleft, the expectation being 677 to 226 in each case. There 

 is obviously a considerable deficiency of cleft, while black agrees 

 closely with expectation. It may be readily observed that there 

 is no evidence of linkage between cleft and black. 



Summarizing the F2 generations from matings (105) and (109), 

 there are 803 gray, 248 black, 123 cleft, and 42 black cleft. There 

 are 926 gray to 290 black and 1051 normal to 165 cleft. The 

 expectation in either case would be 912 to 304. There is clearly, 

 then, a great deficiency of cleft. Among the normal there are 

 803 gray to 248 black where the expectation is 788 to 263 and 

 among the cleft there are 123 gray to 42 black where the ex- 

 pectation is 124 to 41. There is, then, no evidence of linkage 

 between cleft and black. 



2. Free segregation of cleft and sooty. Sooty base showed in 

 a large proport on of the offspring of pair (109), but while very 

 pronounced in some individuals it graded into type in others. 

 This gradation was due in large part at least to the presence of 

 dark mid-area. The moths were classified, however, in a more 

 or less arbitrary manner in relation to this character. The 

 progeny of pair (109) may have been of mixed composition as 

 regards sooty, since the male parent may have been heterozygous. 

 The Fo generation showed cleft distributed apparently without 

 reference to sooty. If complete linkage occurred between cleft 



THE JOURNAL OF EXPEEIME>fTAL ZOOLOGY, VOL. 28, NO. 3 



