856 H. H. NEWMAN AND J. THOMAS PATTERSON 
in various guises, but the underlying inquiry has remained un- 
changed. In one of its older forms the question is phrased: 
“What is the relative potency of nature and nurture in develop- 
ment?” In some of its more modern phases it appears in terms 
of ‘predetermination versus epigenesis,’ ‘blastogenic versus soma- 
togenic variation,’ and ‘heredity versus environment.’ 
In spite of the antiquity of the problem very little direct evi- 
dence has appeared for its solution. So far as we have been 
able to ascertain, the only facts that seem to throw any clear 
light on the situation are those furnished by cases of human 
‘identical’ twins. As long ago as 1875 Galton showed his appre- 
ciation of the value of such data in his paper entitled ‘‘ The his- 
tory of twins, as a criterion of the relative powers of nature and 
nurture.’ In a subsequent paper (Galton, 92) he made use of 
finger-prints as criteria for distinguishing between twins and as 
a suitable character for testing the degree of likeness and unlike- 
ness of such pairs. That he had a deep insight into the under- 
lying fundamental problems involved in the situation is shown 
by his remark: “It may be mentioned that I have an inquiry 
in view which has not yet been fairly begun, namely to determine 
the minutest biological unit that may be hereditarily transmis- 
sible. The-minutiae in the finger-prints of twins seem suitable 
objects for this purpose.”’ 
In 1904, Wilder, interested in the same problem, presented a 
comprehensive review of the whole subject in his paper on ‘‘ Du- 
plicate twins and double monsters.’ His results are of great 
interest and will, we hope, assume a still greater significance in 
the light of the facts here presented. Wilder discovered a sur- 
prising degree of resemblance between the palm and between the 
sole patterns of duplicate twins and was able, he thought, to clas- 
sify twins as ‘fraternal’ or ‘duplicate’ on the basis of this resem- 
blance. In addition, the following phenomena were observed in 
the majority of cases, but were not universal: 
(1) A bilateral correspondence in the palms and soles of each 
individual of a set. 
‘‘(2) A reversal of the finger patterns in either of the right or 
the left indices. 
