The purpose of this article is to show the progress and variation of ossification and growth in the hands of young children, the interrelation of these processes and their significance in respect to other physiologic traits.
As part of the data for the five year study of mental and physical growth of the preschool child, the Bureau of Educational Experiments in New York undertook the collection of roentgenograms of the hand and forearm of each child in Groups 3 to 6 of the City and Country School and the Bureau's own Nursery School. The material here employed represents that collected during a three-year period, from January, 1925, through November, 1927. The roentgenograms were taken at intervals of three months throughout the school year, a program still in operation, with the addition, for a later study of skeletal relationships, of pictures of the foot and shoulder.
The total number of children