Egg Shell Color in Crosses Between White- and Brown-Egg Breeds

THE fact that certain breeds of fowl lay only white eggs, others lay brown or tinted eggs, while still others lay blue eggs, suggests that the color of the egg is determined by hereditary factors. The extreme variation observed in the color of hens’ eggs makes this character one of considerable interest to the biologist. Egg color is also of interest to the economist as preference on the part of consumers for white or for brown eggs leads to price differences which may affect the returns to poultry producers. This results in the so-called white or brown egg markets. Klose and Almquist (1937) report that the pigment in egg shell membrane was identified as a natural porphyrin and that it was identical with protoporphyrin which Fisher has indicated as the porphyrin pigment occurring in all pigmented egg shells. REVIEW OF LITERATURE Observations on shell colors have been made by several . . .