Published data on the normal blood picture in adolescence are relatively scarce and show considerable disagreement.* In some instances the observed differences undoubtedly are attributable, at least in part, to the difference in the altitude at which the subjects were residing; in others no such ready explanation is available. Furthermore, in some of these data a wide range of hemoglobin values and red cell counts is reported for each age group. The question may be raised whether such marked differences represent normal variations and should be expected to occur in a group of subjects all of whom are in superior health.
In September, 1947, and again in 1949, we had the opportunity of studying the blood picture of a highly selected group of healthy rural youths. These were the 4-H Club boys and girls who had been chosen by the local physicians as the health champions of their respective counties