70 INHERITANCE OF DIGITAL MALFORMATIONS IN MAN. 



in each case is greatly reduced in length, — so much so, especially 

 in the thumbs, that they are said to have ''double jointed 

 thumbs." The radiograph (Plate xxvi) shows the first phalanx 

 to be about 12 mm., and the distal 22 mm., respectively in 

 length. Hence, the thumbs thus shortened have the same 

 relation to the other two phalanged digits that exists in the 

 normal hand. Each of the fingers has but two phalanges in- 

 stead of three. The metacarpal bones are normal except in 

 length, being reduced in relative proportion to the length of 

 the digits. The following table gives the length in millimeters 

 of metacarpals and phalanges. 



TABLE L 

 Length of Metacarpals and Phalanges. 



Metacarpal. I^roximal. Middle. Distal. 



Thunil) 34 mm. 12 mm. — 22 mm. 



Index 55 " 30 " -- 15 " 



Middle 55 " 40 " -- 15 " 



Ring 46 " 32 " -- 15 " 



Little 42 '' 22 '' -- 18 '' 



The length of the hand is 162 mm., and the width 94 mm. 

 In a few cases the distal phalanx of the ring finger is not in 

 line with the proximal, but inclines toward the middle finger. 



The hands of all are broad, thick, and pulpy, as is seen in 

 the photographs of the hands (Plates xxiii, xxiv, xxv). The 

 joints of fingers and toes, as appeared on examination and as 

 shown by the radiographs (Plates xxvi, xxvii), are loosely 

 articulated. This may account for the lack of strength in the 

 hands which was spoken of by many. One man, who has been 

 a noted wrestler, said that his defeats were due to his weak 

 hands. The table ii also shows a weak grip. This, however 

 was not a fair test as the instrument used was too wide for 

 their short hands. 



The feet, as shown in the cast and the outlines of the radio- 

 graph (Plate xxvii), do not outwardly appear abnormal. The 

 toes are slightly shorter and the foot a little thicker than normal 

 but not enough so to attract attention. The bones, however 



