In this study, author Frederick P. Thieme presents data on biological characteristics of the population of Puerto Rico. He includes data on nutrition, dental status, intestinal infestation, blood types, and more: data he gathered during fieldwork in 1948 and 1949. Thieme's goals were to set up a baseline as a point of comparison; to study the relationship between physical variability and environment; and to pave the way for establishing medical standards for Puerto Rico.