Witch's Milk and Witches' Marks *

The term witch's milk, referring usually to the mammary secretion of newborn infants,t is an example of that small group of medical and biological words and phrases which had its origin in the popular vocabulary of past centuries. (Freemartin2' is a similar term.) Such expressions lack the classical dignity of Greek and Latin ancestry, but they have a flavor and interest of their own. What was the source of the phrase witch's milk, with its implications of superstition and sorcery, and how has it persisted to take its place in modern scientific terminology? Although little attention is given to the phenomenon in modern textbooks of pediatrics, it is well established that during the first weeks after birth the mammary glands of some babies hypertrophy and produce a colostrumlike secretion. Normally the secretion soon ends, and the glands regress. Partly on the basis of an important study by Lyons,' it is now generally believed that two maternal hormones, estrogen and prolactin, which during the later stages of pregnancy are preparing the maternal mammary glands for lactation, may escape into the fetal circulation in sufficient quantity so that the same phenomenon appears in the infant. If this theory is correct, the transitory production of witch's milk can be explained by the obvious fact that the availability to the baby of the maternal hormones ceases at birth. However, since prolactin has also been found in the pituitary glands of fetal calves,6 it is possible that a brief activity of the baby's pituitary gland may also help to account for the appearance of the secretion. To turn from the significance of the phenomenon to the significance of the phrase is to look back on the dark and evil history of witchcraft, on a record of inspired ignorance, unresisting credulity, and complacent cruelty. The record is certainly incomplete, and part of it is very nearly inaccessible. For our purposes a start may be made with an ancient belief that there existed a variety of demons which had the appearance of birds.' These creatures, feared because they were thought to suck the blood of infants, were called Striges. (The scientific name Strigidae much later was applied