Constitution of the White Leghorn Breed. 155 



color-pattern; and, in addition, of producing a new type of fowl 

 through the isolation, and subsequent employment in breeding, of a 

 previously hidden factor. 



The barred color-pattern is doubtless a very old and a b}^ no means 

 uncommon form of marking in the plumage of both wild and domestic 

 birds. With some modification it is present in the feathering of many 

 of our game birds, but it is in one or two varieties of domestic fowl 

 that the character is to be seen in the purest and most extended form. 

 At the present day the Barred Plymouth Rocks, an American breed, 

 represent by far the most perfect development of the barred pattern 

 to be found in any species or variety of bird. 



The origin of barring in domestic fowls is not easy to ascertain. 

 It appears probable that the barring used in making the breed of 

 Barred Plymouth Rocks as it is known to-day was derived from the 

 American Dominiques. These birds, which possess less perfect 

 barring than the Barred Plymouth Rocks, are stated by some to have 

 inherited this marking from the ^'cuckoo" birds of England, but this 

 point is not supported by available evidence. It must therefore be 

 concluded that we are not acquainted with the manner by whicn the 

 definite barred color-pattern Was first introduced into the breeds of 

 domestic fowl. So far as can be ascertained, however, no new breeds 

 of barred fowl have been produced since the making of the American 

 Barred Plymouth Rocks, in which, as has been stated, the Domi- 

 niques were the major component. A partial exception to this state- 

 ment is found in the words of Wright (1910), who states that barred 

 birds are sometimes the result of crosses between white birds and those 

 of dark color. Wright assumes that barring is not a primary char- 

 acter [unit character], but a sort of mixture through which the breed 

 of Dominiques may have been founded. He further observes that 

 when once produced, this character '^has a strong tendency to per- 

 manence." These opinions of Wright were based upon observations 

 made from time to time in the poultry yard and without especial 

 study. Within the past few years, however, the method of in- 

 heritance of many characters in fowl has been made by several 



