1. Foreword. The Fitter Families' Project is a legitimate outgrowth of scientific agriculture. It is the application of the principles of scientific plant and animal husbandry to the next higher order of creation, the human family, and contemplates the development of a science of practical human husbandry. The basic principle underlying modern agricultural procedure is the fact that the character and vitality of every living thing is determined by two factors, heredity and environment. After the germ cell of plant or animal is fertilized, nothing can alter the traits that plant or animal will have, but it then depends entirely upon the nurture and care as to whether that plant or animal will become the best possible individual of its kind. It is now believed that the time has come when these two factors must be taken into consideration in human mating and in family habits, if the best elements of our civilization are to dominate or even survive. This must be done by stimulating the interest of intelligent families and arousing a family consciousness by which each family will conceive of itself as a genetic unit with a definite obligation to study its heredity and build up its health status. The movement for the competitive health examination of pre-school children originated at the Iowa State Fair in 1911, and the winners provided the climax in the million dollar parade of prize stock and other agricultural products, as they rode in an automobile with a runner on the side proclaiming them to be "Iowa's Best Crop". The examiners of these babies followed the only criterion extant at that time and observed and used, in considerable part, the methods of the stock judges. They soon observed that the stock judges always took inheritance into consideration in judging. Charles B. Davenport said to the Iowa group in the very beginning, "You Jun 1928