The Yucatan Medical Expedition of 1929 undertook to study syphilis among the primitive Maya Indians who still inhabit the interior of Yucatan. It seems quite certain that these Maya are of essentially pure stock (1) and it is believed that they are descended from the people who lived in this region at the time of the Spanish Conquest.
The Expedition not only examined a large number of cases for physical evidence of syphilis and of yaws but also carried out serological examinations of blood specimens from two representative series of cases.
The location of the Archaeological Station of the Carnegie Institution at the old Maya capital, Chichen Itzá, near the center of the northern part of the peninsula, was well adapted for this phase of the work. Not far distant in one direction are the villages and towns of Yucatecans, most of whom in this region have both Spanish and Maya blood, whereas in the other direction are many “bush villages” inhabited by primitive Maya Indians.