GENETIC STUDIES IN POULTRY. 



IV. ON THE BARRED PLUMAGE OF CERTAIN BREEDS. 



By R. C. PUNNETT, F.R.S., and M. S. PEASE, M.A. 



(With Two Text-figures.) 



The type of plumage known as barred, in which bands of different 

 colour are arranged alternately along the feather at right angles to 

 its main axis (cf Fig. 1, p. 239), is characteristic of several breeds of 

 poultry. It is to be found in its most marked form among Plymouth 

 Rocks, Pencilled Hamburghs and Campines. Probably also the feather 

 patterns designated as laced, pencilled\ and .spangled are intimately 

 connected with the barred. We have long felt that a genetic analysis 

 of barring in Poultry, with its peculiar rhythmical alternation of pig- 

 ment deposition in the feather, might help to throw some light upon 

 the problems of growth, and with this end in view we have recently 

 commenced a series of breeding experiments. Though the work is as 

 yet but in its initial stages, the present season has yielded a result of 

 sufficient interest to place on record. Before doing so however we would 

 dwell briefly upon what is known as to the genetic behaviour of barring 

 in poultry. 



In the present state of our knowledge it would appear that the 

 barring found in Plymouth Rocks, Scots Greys and Dumpies is geneti- 

 cally distinct from that found in the barred breeds of Hamburghs, and 

 in Campines. In the Rock group the birds are of the same fundamental 

 colour throughout, and the barring effect is produced through full and 

 faint development of this fundamental colour in alternate bands. In 

 the Barred Rock itself, for example, the darker bands appear as grey- 

 black, while in the lighter bands the grey colour is very faint, so that 

 these bands appear almost, though not quite white. 



1 The use of this term in the Fancy is apt to confuse the uninstructed. The "Pencilled" 

 Hamburgh is a barred bird. We propose, for purposes of this investigation, to restrict the 

 term "pencilled" to the characteristic pattern of the feathers in the " Partridge " varieties 

 of Cochins, Wyandottes, etc. The connection between pencilled and barred is a close one, 

 for feathers that would pass for barred, as well as the distinctive pencilled feathers, and 

 intermediate types, are to be found on the same bird. 



