302 RAYMOND PKARL. 



r n 



cf unknown Faintly barred white 9 



Fi Generation (i) bwNf . BWnF 



or 

 (2) bwnf . BWnF 



Of these two alternative formulae in FI the first is decidedly 

 the more probable, since there is every reason to expect that (2) 

 would be a pure white bird showing somatically no trace of 

 barring. 



In the Fo generation got by mating the faintly barred white 9 

 of FI to the black cf of the P generation the females were barred, 

 indicating again that one of the gametes uniting to form these 

 individuals must have borne both F and B, since no gamete from 

 the sire could bear either of these factors. 



It is evident that in interpreting this case we are forced to 

 adopt either one or the other of two alternatives, both of which 

 present novel points in comparison with the results of recent 

 experiments regarding the inheritance of the barred pattern in 

 crosses involving Barred Rocks, in which this pattern is well 

 fixed. On the one hand we may conclude that the White Booted 

 9 original parent carried the B factor in its gametes. This 

 interpretation leads to the results worked out above, the novel 

 point in which is that here there is no repulsion between B and F 

 in gametogenesis (or coupling between B and / if one chooses that 

 view) as is the case in Barred Plymouth Rocks of the present day. 

 Here a non-barred cf mated with a female eariying barring (by 

 hypothesis) produces barred daughters, \\here there should be 

 produced (to accord with recent experiments on barring) barred 

 sons and non-barred daughters. On the oilier hand it is possible 

 to assume that the faint barring in the FI 9 arose de noro, and 

 ih.it i he White Booted 9 parent did not carry the B factor. < hi 

 this view it must be concluded that this neic character burring 

 when it first appears behaves in an absolutely different way in 

 inheritance from what it docs later. Either conclusion is sufficiently 

 interesting, and stimulating to further research. 



