Medical significance of finger-prints and related phenomena.

In 1684 a learned and ingenious physician, Nehemiah Grew, published the first description of the epidermal ridges which make characteristic patterns when prints are taken of fingertips. These "innumerable little ridges of equal bigness and distance, and everywhere running parallel one with another," contain the pores of the sweat glands. Grew also noted that they were disposed into " ellipticks " and " triangles." Grew's paper was followed by the publication in Amsterdam of a brief account in Bidloo's (1685) Anatomia Humani Corporis. In the year after that, 1686, a comparable description was given by Malpighi in De Externo Tactus Organo. For nearly a century and a half there were no notable advances, but in 1823 Purkinje, in a thesis, again written in Latin, described nine types of patterns (or varieties of curvature) on the fingers. The first systematic study of the whole subject, however, was carried out by Francis Galton (1892) around the year 1890. His early interest was in the value of finger-prints for personal identification, for they persist throughout life. The chief use of identification was, he remarked, to benefit society by detecting rogues rather than to establish the identity of men who were honest. He made a thorough inventory of different kinds of pattern and drew attention to the fundamental formations-arches, loops, and whorls (Fig. 1). He also made