Abstract Part I 2 of these studies dealt with the practical and theoretical importance of questions of “egg quality,” including under the term such characteristics as yolk color, albumen color and consistency, shell thickness and texture, and the like. It also contained a brief review of the literature of one phase of the subject, that of yolk color; a description of the material and methods used in the present investigations, which have been carried on continuously since December, 1923; and a summary of some of the principal results which had been obtained up to that time. Only one of these results will be mentioned here. It seemed to be demonstrated conclusively that the most important factor influencing yolk color was the amount of greens actually eaten by the birds. This was shown by three different kinds of tests: first by field tests, taking random samples of eggs from different flocks, getting the . . .