A Modification of the Sex Ratio, and of other Ratios, etc. «35 



A few more (6) of the long winged females from the la.st cross 

 (of the 99) were bred to three long winged brothers, and gave the 

 following results: 



L 9 286 L cJ 33 M d Ii6 R (^ 25 Rud.-min. (J 10 



If we assumed that these females had the composition RmXrMX 

 (which is the class that is five times more likely to be present) and 

 that the male had the composition RMX (which is the only long winged 

 class of males) the results are worked out in the following table: 



Similarly, a few miniature females (6) in the same cross (of the 

 104) were mated to a few (3) of the miniature males (of the 99) 

 and gave: 



]\f 9.114 M (5 58 Rud.-min. (5 23 



Three other cases of miniature Fi females were tested with 

 miniature males. All three results gave the same classes, which 

 added together gave: 



M 9 694 M cJ 342 Rud.-min. (J 98 



The analysis of this case is as follows: 



rMX — rmX = Fj Min. $ 

 rMX — rm = „5 



rMXrMX = Min. 9 

 rmXrMX = „ 9 

 rMXrm = „ (5 

 rmXrm ^ Min.-rud. (J 



The analysis shows that the number of miniature males corre- 

 sponds with e.vpectation (i. e., half the number of the females). The 

 deficiency of the rudimentary-miniature males must be explained as 

 the result of viability. 



