No. 559] 



BARRED PLUMAGE PATTERN 



427 



barred. The only way to avoid this difficulty is to embody 

 in the tables no chicks which die under three weeks of 

 age. This plan was adhered to in the collection of data 

 presented in Table II. 



Regarding the barred birds, it is clear that more are 

 called for than actually appeared; but, as already ex- 

 plained, the number would probably have been made up 

 by addition of birds from the blacks, if these chicks had 

 lived long enough to develop their barring. It is appar- 

 ent, however, that the ratio of males to females is in the 

 right sense. 



Turning now to the results of similar matings pre- 

 sented in Table II, it is apparent that the experimental 

 results conform more closely to the expected. In this 

 case all the chicks were over three weeks old when de- 

 scribed. The obtained ratio of whites to blacks is 106 : 31, 

 while the expected is 102 : 35. The actual ratio of black 

 to barred birds was 7 : 24, while the expected was 

 8 -f- : 25 -f. As was to be expected, no black males ap- 

 peared, while the number of barred males was approxi- 

 mately twice the number of the barred females (14:6), 

 the expected being 17 + : 8 -f-. 



It is thus clear that when only chicks over three weeks 

 old are included in the tables, the actual and the expected 

 ratios find close agreement, and appear to demonstrate 

 the correctness of the view that the male White Leghorn 

 fowl is homozygous for the barred plumage pattern. Evi- 

 dence similar to that presented above has been secured 

 from matings of White Leghorn J with Black Minorca, 

 Black Java and Black Spanish hens. Crosses involving 

 the White Leghorn $ have not yet been made, but it seems 

 likely that these fowls are heterozygous for the barred 

 character, which probably follows lines of inheritance 

 similar to the barring of the Barred Plymouth Eock 

 breed. In the White Leghorn breed, of which several 

 different males have now been tested, the barred pattern 

 appears to exist as a cryptomere, much as in the breed of 



