Constitution of the White Leghorn Breed. 169 



from that present in the Barred Plymouth Rocks. It corresponded 

 well with the barring depicted in early illustrations (see Pearl, 1911, 

 p. 306) of the Barred Plymouth Rock breed as it existed years ago, 

 before it had been developed to the present state of perfection. 



As has been stated, it is impossible to ascertain when chicks are in 

 the down whether they may later develop barring. For this reason 

 the ratio of black to barred birds as expressed in Table 3 probably 

 does not represent the actual ratio. In order to avoid this source of 

 error, there was made in 1912 a second series of crosses between Fi 

 W. L. X B. H. stock, reared in 1911 from new birds not employed in 

 the 1910 matings. In compiling the records of these F2 individuals 

 no bird that was less than 3 weeks of age was entered. This precau- 

 tion made it possible to discriminate carefully between black and 

 barred birds, and results in some difference in the totals. 



The results of this series of matings (Table 4) were essentially the 

 same as in the 1911 series, save in the black : barred ratio. The 

 barred birds showed the same sort of barring and all circumstances 

 indicated that the appearance of this character in F2 was in accord- 

 ance with some definite law. This point is discussed in detail on 

 p. 193, and we may now turn our attention to the results of other 

 crosses involving the W. L. stock. 



Case 2. — White Leghorn d^ X Black Spanish 9 . Nature of mating: 

 CCBBffll X CCbhFfii. (For discussion, see p. 186). 



In this series of matings the results of the 1910 and 1911 breeding 

 are combined. In 1910, W. L. 193 A was employed; in 1911, W. L. 

 1 A.* In the 1910 matings. Black Spanish 99 181 A and 182 A 

 were employed.! In 1911 B. S. 99 13 A, B and C were used.f 

 The Black Spanish 9 181 A, typical of the others, was described as 

 follows : 



♦Obtained from Charles J. Fogg, Waltham, Mass. 



tObtained from the Groesbeck Poultry Farms, Hartford, Conn. 



JObtained from M. H. Lindsey, Northville, N. Y. 



