4. Doubling the number of chromosomes in yellow corn increased the carotinoid content 43 per cent as determined by chemical analysis of 2N and 4N stocks having a common origin. The volume of the endosperm cells of the tetraploid was more than 3.5 times as great as that of the diploid. Thus the individual endosperm cells of the tetraploid contained more than 5 times as much carotinoid as did those of the diploid and in terms of gene concentration within the endosperm tissue the amount of carotinoid was increased 2.5 times as a result of chromosome doubling. Chemical analyses by D. B. Hand.