SOLE PATTERNS OF TWINS. 299 



Twins 119-120. The general type of patterns found are not 

 a very common variety. The ridge counts from the second to 

 the third plantar areas are: ngR, 395 U9 L i 37; I2OR, 27; 

 I20L, 25. 



Twins 133-134. In this set the twins are of opposite sex. 

 This type of pattern is of common occurrence. 



Twins 151-152. The plantar patterns on both left feet have 

 a "V" shape. 



Twins 169-170. This type of pattern is uncommon. 



An attempt was made to count the ridges from the various 

 landmarks, but they vary so greatly in most instances that it 

 was not thought worth while to report all of the figures. The 

 striking similarities are given above. 



The individual patterns occur in almost the same ratio as 

 those found in a previous series. 6 



The fact that twins 133-134 are of opposite sex might lead 

 one to conclude that study of the sole prints is without value in 

 determining the type of twin under consideration, but I feel 

 that such is not the case. They are of the Ai type, one of the 

 simplest and commonest. I have found that Ai patterns occur 

 about 10 per cent, of the time on both feet, and so do not think 

 it unreasonable to assume that their presence in this set of twins 

 is an accident. 



In order to determine whether or not patterns of the same 

 formula might be found on all four feet of ordinary (not twin) 

 brothers and sisters, the prints of 38 pairs (the only ones available 

 at this time) were examined. Of these 10 were female-female, 

 12 male-male, and 16 female-male. One pair of sisters had the 

 same patterns, but they were of a very common type, 



CONCLUSIONS. 



A study of the above data leads one to the conclusion that 

 the presence of identical patterns on the soles of a pair of twins 

 might point to their monozygotic origin, but as Newman states, 

 their absence does not disprove it. A study such as this is, 

 of course, not conclusive, but it points the way for further 

 investigation. It was undertaken in the hope that sole patterns 



might reveal some information as to the origin of twins. If the 

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