Just what growth is, why it happens, how it can be influenced and why it is frequently abnormal are questions of great importance. This is especially true in relation to the great advances that have been made in our knowledge of nutrition. Heretofore most of the studies of growth have dealt mainly with the determination of changes in weight and height, the statistical analysis of these values and the correlation between them.
In a recent series of publications with the general title "On the Motion of Growth," Norman C. Wetzel has indicated clearly that there is little to be learned from more studies of growth that are limited in their scope to the measurement of absolute changes in weight and height alone. This investigator regards growth as a mode of motion and treats it by the methods of energetics and classic dynamics. This fundamental and original method of attacking the