was chief of the department until his resignation in 1920. Since that date, the writer has had the honor of holding this important position. The figures and tables are presented often without explanation, and always without apology. Some are apparently contradictory, but they must be taken at their face value. The work has been shared by the entire staff, each in his turn, some having more ability and experience than others. It is believed that because of this fact, and because this review cov-
No takes yet. Share an insight, caveat, or question.
Barney et al. (1937) studied this question.