4iz 



THE QUARTERLY REVIEW OF BIOLOGY 



sole patterns of twins which has appeared 

 to this day. 



The material which has formed the 

 basis of my study consists of 9 sets of palm, 

 sole and finger prints and 55 sets of 

 palm and finger prints of same-sex twins, 

 9 sets of palm and finger prints of differ- 

 ent-sex twins and one set of palm and 

 finger prints of male triplets, obtained 

 mainly from among the school children of 



1904, 1916; Wilder and Wentworth, 1918). 

 Especially, it has been found advisable to 

 take into consideration as many available 

 characteristics of the patterns as possible. 

 Thus, for finger patterns, besides the 

 number of ridges, certain other charac- 

 teristics, for instance, the ratio of the 

 height and breadth and the tendency 

 towards twisting mentioned by Bonnevie 

 (19x3, 19x4), and also the length of each 

 ridge, have been considered. For palm 

 patterns, the number of ridges intervening 



ft 



E.;>v.1 



Fig. 1. Brothers Including a Pair of Identical Twins 

 The twins were born with a common chorion and placenta. Both are graduates of the Kyoto Imperial 

 University. 



the city of Kyoto. This material has 

 been greatly supplemented by the collec- 

 tion of Mr. Obonai, who generously put 

 them all under my examination. These 

 include finger prints of 166 pairs of same- 

 sex twins and 30 pairs of different-sex 

 twins obtained from among the school 

 children in the city and suburbs of Tokyo; 

 and some are accompanied by palm 

 prints. 



The formulation of the patterns and 

 ridges has been done largely after Wilder's 

 scheme with a slight modification (Wilder, 



between the main lines has been counted 

 and the various shapes of the hypothenar 

 pattern recorded. In addition to the 

 data obtained from the examination of 

 the above material, I have consulted, for 

 drawing general conclusions, the data in 

 the works by previous authors, especially 

 by Wilder (1904, 191 9), Poll (1914), 

 Ganther and Rominger (1913), Lauterbach 

 (19x5), Montgomery (19x6), Kuragami 

 (19x6) and Kishi (19x7). 



Lack of space prevents me from going 

 into the details of the study, and I can only 



