"Milagros are part of an ancient folk custom that transcends the centuries and the boundaries of diverse cultures. The practice of offering to a diety miniature items that in some way symbolize one’s concerns seems to be nearly universal and timeless. The uses and forms of these miniature body parts and human figures appear to be virtually unchanged from at least the classic period in Greece to the present day in those part of Latin America where milagros are still part of folk traditions.These miniatures are known in Spanish as milagros which literally means “miracles’’. Because milagros are primarily offered to a Saint in thanks for his or her answering a petitioner’s prayer, these miniatures commemorate a ‘miracle’ - a baby cure of illness, a son returned home safely from a war, and so on. Because they are a type of votive offering, milagros also are often referred to as ex-votos, a Latin term meaning “from a vos”. The designation “ex-voto’ however, refers to a variety of offerings made by the faithful to their favorite saint or omega of Christ or the Virgin."
Milagros, Votive offerings from the Americas, by Martha Egan