Studies on Inheritance in Poultry. 
459 
In thus demonstrating the constitution of the White Leghorn with 
reference to factors for black pigmentation these results posse ss a 
significance in the field of practical breeding. It is not uncommon 
for poultrymen to employ the White Leghorn in crosses with othei 
breeds to improve certain characters. In so doing it is usually 
assumed that since the White Leghorn is ostensibly white, and 
lacking visible pattern, the admixture of Leghorn blood can be made 
without introducing complexities in either pattern or color. 1 lie 
results of the present study, as well as the experience of many poultry- 
men, indicate clearly that such a procedure is open to considerable 
danger if the breeder desires to foster race-purity in his stock. The 
fact that the White Leghorn carries both black pigmentation and 
factors for barred plumage pattern means that in F 2 and latei genei- 
ations these characters may appear to the detriment of the breed. 
Black, which through years of persevering selection has perhaps 
been eliminated from buff, may be unconsciously re-introduced 
under the cloak of the Leghorn dominant white. Dark barrings 
and cuckoo markings, from which a race may have been quite purified, 
may re-enter under the apparently patternless feathering of this bleed. 
To know the constitution of the race, to know the factors that lie 
hidden in the germ plasm, as well as those characters that are on 
parade, enable the intelligent poultryman to make use of desirable 
characters to the best advantage; and at the same time, to avoid 
those errors in breeding which result from insufficient knowledge 
of the fundamental constitution of the race involved. 
(OVER) 
