Huge seasonal migrations take place in the United States every year with apparent regularity and with constantly growing volume. More than 35,000,000 people take part in these migrations, using all means of transportation and spending the incredible but carefully estimated sum of $5,000,000,000 yearly. These migrations are not studied from a medical point of view nor are they directed or supervised. They lack a conscious, well recognized purpose and are governed mostly by vogues, whims and fads born out of hearsay evidence. The public might derive optimal health benefits from these migrations but never will unless the medical profession will recognize and develop the enormous possibilities lying dormant within them.
The following data on the five important factors of these migrations were collected by inquiries to state health, conservation and highway departments:
1. Seasonal Characteristics.—
The greater portion (about 70 per cent) of the migrations take place in the