On the other hand, snppose that a competent expert has examined his bone and muscle structure, ascertained his weight and height, and tested his mental development. These things are definite and indisputable, and prove what the "me fourteen" argument can never prove; mature preparedness for work.
No age limit can be fixed which will apply fairly or even adequately in a cosmopolitan country like the United States. Some races mature earlier than others, and in every race, individuals differ in their point of maturity. Some children of sixteen are as well prepared for work as other children of twenty. The real criterion is not, therefore, "How old are you?" but "Are you mature?" Unfortunately scientists have never come to an agreement as to an effective test of maturity. Weight and height are some index; the hardness of certain bones is another index; and the growth of hair on the face and body is still another. As to which one, or which combination of these indices, should be accepted as a rational basis for judging of the matu-
