308 RAYMOND PEARL. 



of the pattern. The pure B. P. R. c? of today is, so far as is 

 known, always homozygous with reference to the barring factor, 

 whatever that may be. He carries two "doses" of B. Somat- 

 ically he is light in color with narrow clean cut bars. When by 

 crossing a male is made carrying but one "dose" of B (i. e., 

 heterozygous in relation to the barring factor) the somatic pig- 

 mentation is markedly changed, and becomes like that of the 

 earliest Barred Rocks known. This obviously suggests that in 

 the early history of the breed the males were regularly hetero- 

 zygous with reference to barring. If so they should have pro- 

 duced, with considerable regularity, non-barred (black) daugh- 

 ters. As a matter of fact this was probably the case. Up until 

 20 years ago, and even later in some localities, one would judge 

 from various statements to be found in poultry journals, agri- 

 cultural papers and the like, that it was not a particularly un- 

 common occurrence for a Barred Rock mating to throw some 

 solid black chickens. 



It is of interest to note that at the time of the original founda- 

 tion of the Plymouth Rock breed the Dominiques, from which 

 the barred pattern was derived, had the same type of pigmenta- 

 tion. This is shown in a contemporary wood-cut of the latter 

 breed, reproduced in Fig. 3. 



This picture of Dominique's was published in the American 

 Agriculturist, Vol. 29, p. 13, 1870. It was drawn by Edwin 

 Forbes from a pair of birds owned by Col. Henry Howland of 

 Chicago. These birds were prize winners in their time. This 

 cut, in a very much garbled form, was reproduced in the Fanciers 

 Journal in 1876, from which source it has been copied by Sewell. 1 



1 Loc. cit. 



