234 Isabel McCracken 



Behavior of the alternate color characters in this generation is 

 entirely consistent with that in previous generations. 



In Table IV, category a, S is dominant in every brood (com- 

 pletely dominant in 14 broods, transmitting B in 22 broods). 

 In no case does the allelomorph, AB, appear. 



In category h, AB is approaching a stage of purity (entirely 

 pure in 27 out of 30 broods). In the three broods in which mosaics 

 occur, there are but four in one brood and two in each of two other 

 broods. Comparison of this category with category a of Tables 

 II and III shows here, in the 4th generation from the sport parent 

 an increasing stability of the sport character. 



In category c, type B is almost completely dominant over the 

 type AB (entirely so, if I is considered to be a modified B in char- 

 acter, as its behavior appears to indicate). 



In category /, where two '06 sports were mated, the result par- 

 allels that of similar matings in the previous year (Table II, cate- 

 gory a) .in the predominance of AB in mixed broods. No broods 

 wholly AB were obtained. 



Submitting categories ^, e, g and /z to a closer analysis, we obtain 

 the following data : 



Category 



^ Extracted B (from ABxAB) X hybrid B (from ABxB) = i B brood, 9 mixed 

 broods (B:AB as 14:1). 



If Hybrid B X hybrid B = 10 mixed broods i g 



f R 

 g Extracted Bx pure B* =20 mixed broods ^ g 



AB as I :i — I brood. 



AB: I as 7:2:1 —6 broods. 



AB as 2:1 — 14 broods. 



; TT I • 1 Ti T^* T^ • , 1 I B: AB: I as 13: I :i —3 broods. 



h Hybrid Bxpure B* = 10B, 5 mixed broods ^g.^g^g^.j _^ j^^^^jg 



AB: I as 9:7:1 —9 broods. 



*Pure in the sense of having no previous contamination with AB. 



The following results are noticeable: 



1 The total exclusion of S. 



2 The unexceptional predominance of B over AB and I in 

 mixed broods. 



3 The large preponderance of exclusively B broods where 

 pure B meets hybrid B. 



