INHERITANCE OF EGG CHARACTERS 



23 



E. Egg Shell Color 



Shade of color has been studied by a number of workers already mentioned, 

 particularly the results from crossing breeds having different egg-shell color. 

 The studies here reported are concerned with pigment flecking on the shell and 

 with shades of shell color in the Rhode Island Red breed. Eggs often carry 

 brown pigment flecks that are irregularly distributed. These flecks may occur 

 on shells of several shades of color but are more likely to occur on the darker 

 shades. 



Shell Flecking 



In Table 10 are presented the experimental results in breeding from dams 

 laying flecked eggs and dams laying uniform eggs. 



Table 10. — Egg-Shell Flecking 



Dams Classified by Shell Flecking 



Shells necked 

 Line A 

 Line B 

 Line C 



Shells Uniform 

 Line A 

 Line B 

 Line C 



The gross data in table 10 indicate that shell necking is not an inherited 

 character because the group of dams laying flecked eggs and the dams laying 

 eggs of uniform color produced the same proportions of daughters laying 

 necked and uniform eggs. There was furthermore no significant difference 

 in the three lines with respect to shell flecking. Evidently the distribution of 

 shell pigment is purely physiological and is not governed by inheritance. 



Shades of Egg Shell Color 



The shades of shell color in the Rhode Island Reds used in this experiment 

 nearly approached the series given in Ridgeway's plate 29. The shades con- 

 cerned ranged from white to vinaceous cinnamon. These nine shades did not 

 correspond in color with all of the eggs but are the nearest approximation that 

 could be selected. The following eight shades are included: white, pale pinkish 

 buff, pale pinkish cinnamon, pale cinnamon pink, pinkish buff, light pinkish 

 cinnamon, light vinaceous cinnamon and vinaceous cinnamon. 



The egg color of the daughters produced by the different classes of dams 

 should throw some light on the inheritance of egg color. The five dams laying 

 white or near white eggs produced 42 daughters, one-third of which laid white 

 eggs and two-thirds colored eggs. The majority of the daughters laying tinted 

 eggs fell into the pale pinkish buff class, which is not far removed from white. 

 There were, however, seven daughters in the light pinkish cinnamon group 

 where there is considerable pigmentation. 



