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OCR Rendition - approximate
58 FINGER PRINTS CHAP them. The distance between adjacent pores on the same ridge is, roughly speaking, about half that which separates the ridges. The lines of a pattern are such as an artist would draw, if dots had been made on a sheet of paper in positions corresponding to the several pores, and he endeavoured to connect them by evenly flowing curves ; it would be difficult to draw a pattern under these conditions, and within definite boundaries, that cannot be matched in a living hand. The embryological development of the ridges has been studied by many, but more especially by Dr. A. Kollmann,' whose careful investigations and bibliography should be consulted by physiologists interested in the subject. He conceives the ridges to be formed through lateral pressures between nascent structures. The ridges are said to be first discernible in the fourth month of foetal life, and fully formed by the sixth. In babies and children the delicacy of the ridges is proportionate to the smallness of their stature. They grow simultaneously with the general growth of the body, and continue to be sharply defined until old age has set in, when an incipient disintegration of the texture of the skin spoils, and may largely obliterate them, as in the finger prints on the title-page. They develop most in hands that do a moderate amount of work, and they. are strongly developed in the foot, which has the hard work of 1 Der Tastapparat der Hand der menschlichen Rassen and der Affen. Dr. Arthur Kollmann. Leopold Voss, Leipzig, 1883. He has also published a more recent memoir.
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