THE INHERITANCE OF THE PECULIAR 

 PIGMENTATION OF THE SILKY FOWL. 



By W. BATESON, M.A., F.R.S. 

 AND R. C. PUNNETT, M.A. 



CONTENTS. 



PAOB 



Introduction 186 



General statement of resnlts 186 



Detailed results of the various crosses 191 



(1) The Fi generation 191 



(2) The F2 generation 192 



(3) Fi X Brown Leghorn 194 



(4) Fi X fully pigmented birds 195 



(5) The fully pigmented F^ birds 197 



(6) The ppii strain : a test of the hypothesis . . 197 

 The constitution of the Brown Leghorn hen .... 199 



Exceptions 200 



The grades of pigmentation 200 



Silky crosses other than with Brown Leghorns . . . 202 



Introduction. 



During the past six years we have been engaged upon a series of 

 experiments connected with the inheritance of the peculiar pigmenta- 

 tion of the Silky Fowl. A brief account of the general features of this 

 interesting case has already been published by one of us\ but as our 

 experiments are now concluded we are able to give in greater detail 

 the evidence upon which our views are based. As a description of the 

 Silky Fowl may be found in any of the standard works on poultry it 

 is unnecessary for us to dwell upon the characters of the breed except 

 in so far as they enter into this particular series of experiments. One 

 of its most remarkable features is the extraordinary abundance of black 

 pigment which is generally distributed among most of the mesodermal 

 » W. Bateson, Mendel's Principles 0/ Heredity, 1909, p. 181. 



