858 H. H. NEWMAN AND J. THOMAS PATTERSON 
TABLE 1 
Showing physical statistics of Wilder’s twins 
ser Sue Gos es oe AGE IN YEARS 
Te eee de en eae 27 2.39 21.10 
THA kira e kee eden 27 2.35 lyf lil 
TUIEVSY,. Set ar ee ewe 27 1.64 lO 
DA Ga a eeye, Gee SeRee ars et ee 50 1.76 ilefaaul 
Migane 85.5. 2.03 18.1 
Although Wilder realizes that dimensional and other physical 
measurements ‘“‘should be taken during the younger life or at least 
before there is any marked difference in the experience,” yet he 
apparently considers that in all of his four sets, whose ages range 
from seventeen to twenty-one years, “these conditions are met 
with, as they are all those of young people.’’ Seventeen or more 
years of post-natal life would seem, however, to be sufficient for 
the operation of nutritional differences, some of which might tend 
to cause originally identical characters to diverge, and others, 
originally divergent characters to converge. It would seem to 
be inadvisable then to attempt to draw the line between nature 
and nurture on the basis of physical characters so subject to 
modification by environment, for a variation in nutrition alone 
might readily produce all of the differences shown in the sets of 
physical measurements cited. Nutritional differences doubtless 
manifest themselves even before birth, and hence would tend to 
vitiate the results of physical measurements taken on new-born 
duplicates even if such were available. Consequently it would 
seem advisable to limit investigation to those characters which 
reach a definitive condition at an early period and which are sub- 
ject to little or no modifications due to nutrition. The patterns 
of the friction ridges of the palm and sole are characters of this 
sort and should give highly reliable data as to the strength of 
hereditary control. But even this data, interesting and suggestive 
as it is, can be accepted only with a considerable amount of 
reservation; for it has, in common with all other data derived from 
