Harris Hawthorne Wilder 461 



e. Physical measurements of three of the above sets of twins and of 

 one set of which I have no prints. 



f. A i3hotograph of a set of triplets. 



2. The prints allow themselves to be classified in two distinct groups : 



a. Those in which the main lines and other features of palms, soles 

 and finger prints correspond to a remarkable degree. 



b. Those in which the features just named show no greater similarity 

 than in any two brothers and sisters of distinct birth, or between indi- 

 viduals not related. 



3. These correspondences (those in the first group, 2 a) are limited 

 to the course of the main lines of interpretation, and to the type, posi- 

 tion, etc., of patterns or other macroscopic peculiarities, allowing some 

 latitude in the relative size of the various areas. There is no corre- 

 spondence in the characters of the individual ridges (the minutiae of 

 Galton). 



4. In the case of the finger patterns the correspondences are subject 

 to the following exceptions : 



a. The patterns of the index fingers are frequently different from 

 one another, a condition occasionally met with in the thumbs, and once 

 (in the present investigation) in the middle fingers. 



b. In almost 50 per cent of the cases of general correspondence 

 examined (-i out of 9), the patterns of one of the indices, either right 

 or left, are of the same type in the two individuals of the set, but are 

 exactly reversed, being the symmetrical equivalents of each other. 



5. In the case of the palm and sole configuration, where there is a cor- 

 respondence of main lines and other features, there is also usually, 

 though not always, an approximate or exact correspondence between the 

 markings of the right and left side, a relation which occurs occasionally 

 in an individual not of multiple birth, but infrequently. 



6. This correspondence in the configuration of the friction-skin of 

 hand and feet is in all cases (with the exception of No. XIII) corre- 

 lated with that marked correspondence in the physical appearance, in- 

 cluding the facial features, which constitutes the type of twin com- 

 monly known as " identical," here called " duplicate " ; where, on the 

 other hand, there is a lack of correspondence in one of these details, 

 there is in the others also. These latter are called here " fraternal " 

 twins. Out of sixteen sets of twins examined, nine sets of duplicate 

 and six sets of fraternals exhibited the above principles in detail, and of 

 a set of triplets, which consists of two boys and a girl, the boys were 

 typical duplicates, while the girl, as related to the boys, was fraternal. 



7. In set No. XIII, although the two individuals closely resemble one 

 33 



