XXI.—A Study of the Incidence, Distribution and Characteristics of Blood Spots and Miniature Eggs

Abstract

There are two commonly met with types of defective eggs laid by the domestic hen that result in considerable financial loss to the poultry farmer, and are frequent enough in their occurrence to affect perceptibly the potential food supply derived from the poultry industry.The first of these results from the inclusion of blood or meat spots in eggs, and the second is the production of eggs so small as to make the majority of them unsaleable—the so-called “Miniature” eggs.The presence of blood on the yolk of an egg was recorded by Aristotle as early as 300 B.C., and he attributed it to premature ovulation. Later, about A.D. 1600, Fabricius (Adelmann, 1942), during a demonstration of “sanguineous” eggs to his anatomy class, described a livercoloured body included in an egg. The occurrence of blood spots in eggs led both these authors to propound the theory that the yolk was directly formed from blood.