The iodine content of hens' eggs varies directly with the amount of this element in the ration of the bird. The feeding of 2 and 5 mg. of iodine daily per bird, in the form of dried kelp, iodized linseed meal, or potassium iodide, increased the iodine content of the eggs approximately 75 and 150 times, respectively. The percentage of iodine in eggs immediately decreases upon the discontinuance of iodine feeding. The amount of iodine in eggs is independent of the form in which it is fed to the birds.