Monstrosities in man and animals have attracted attention since the earliest times, and amongst primitive and uncivilized peoples have been regarded as of supernatural origin. The human monstrosities were regarded as having been engendered in women by the devil either in his own form or in the guise of some animal. The belief still to be found amongst uneducated persons that un natural union between women and male animals, or between men and female animals, may be fertile and produce monsters, is an at tenuated form of the satanic legend. The scientific appreciation of monsters has grown with the study of embryology. William Har vey (1651) first referred monstrosities to their proper place as abnormalities in embryonic reproduction. E. G. St. Hilaire was the first to attempt experimental teratology and to maintain that many monstrosities were the result of influences causing deviations from the normal course of embryonic development. I. G. St. Hilaire, his son, published an elaborate treatise on anomalies (Paris, 1832— 37) which remains one of the most valuable records of the subject.
A similar treatise with an incomparable atlas of illustrations was issued by W. Vrollik, the great Dutch anatomist, between 1840 and 1849, whilst A. Forster issued in 1861 a textbook with illustrations chiefly from preparations in the museum at Wiirzburg. The great museums devoted much attention to the collection and display of malformations, and there is a magnificent series in the Museum of the Royal College of Surgeons of England, with descriptive catalogues. In 1891 Camille Dareste published his experiments, chiefly on the developing egg of the fowl, not only showing the probable cause of many of the most common abnormalities, but practically creating a new branch of science, experimental embry ology. Teratology has since become an off-shoot of embryology and heredity and must be studied in relation to these subjects.
E. Schwalbe's Morphologic der Missbildungen (1906-19o9) is a very complete study of the modern developments of teratology, with a list of authorities from the earliest times. (C. CR. ; P. C. M.)