44 IOWA ACADEMY OF SCIENCES. 



A STUDY IN THE HEREDITARY TRANSMISSION 

 OF FINGER PATTERNS. 



BY A. A. VEBLEN. 



By finger patterns is meant figures formed by the minute 

 papillary ridges upon the inside surface of the last joint of 

 the thumb and fingers. They are most conveniently 

 studied by inking the fingers with printer's ink and making 

 impressions on paper or any smooth light surface to which 

 the ink w411 adhere. Sir Francis Galton in his work 

 "Finger Prints" and other publications, treats the subject 

 of these patterns exhaustively and scientifically. The 

 patterns are of practically infinite variety. They are also 

 persistent and unchanging through the life of the individ- 

 ual, and are destroyed or obliterated only by violent and 

 deep injuries to the fingers. Finger prints therefore con- 

 stitute a certain and convenient means of personal identi- 

 fication. Though the patterns differ so much on different 

 fingers, they may be classified under three general types, 

 called the arch, the loop, and whorl. In the arch the lines 

 or ridges run in a more or less regular transverse arrange- 

 ment across the finger tip. In the loop the characteristic 

 portion of the pattern is enclosed in a gulf-like or bay-like 

 arrangement of ridges. The bay may open toward the 

 thumb or the little finger side of the hand, or to the radial 

 or the ulnar side. In the present discussion we shall use 

 the terms as Galton uses them, calling these loops ulnar 

 or radial according to the side toward which they open. 

 When the ridges in the characteristic portion of the pattern 

 assume a spiral or circular, or twisted arrangement, they 

 are said to form a whorl. In a very few patterns the 

 arrangement of lines is so irregular or anomalous as to 

 make it difficult to decide as to their classification; but 

 such cases are much rarer than might be expected. 



