206 DR DAVID HEPBURN ON 
the fundamental patterns, yet I believe that I have sufficient 
ground for stating that “whorl” patterns predominate 
among the negro races, and that “loop ” and “ tent” patterns 
are equally characteristic of the white races. Certainly 
“whorl” patterns are remarkably constant among the apes, 
and the presence of this pattern merely indicates the 
existence of a more symmetrical “ pad” area for the basis of 
the “whorl.” The frequence of “loops” and “tents,” on 
the other hand, merely expresses considerable deviation from 
the primitive symmetry of the “ pad” area. 
The entire area of the palm and sole of man and apes, 
not occupied by patterns, is covered by papillary ridges, 
which are arranged in a direction transverse or obliquely 
transverse to the long axis of the hand or foot. 
Their Significance—Having now discussed the presence, 
the classification, and the evolution of papillary ridges in 
connection with pattern areas and non-pattern areas, it is 
necessary to find some explanation of the presence of 
papille in the skin, as well as the arrangement of these 
papille in the form of ridges, no less than the arrangement 
of the ridges in patterns and in non-pattern areas. 
In order that my argument as to the function performed 
by those papillary ridges, whether in the form of patterns or 
as parallel ridges, may proceed intelligently, it is necessary 
for me to premise that papille are everywhere characteristic 
structures in the true skin, but that they are very numerous 
on the palms and soles, and that it is only in these places that 
they arrange themselves in patterns and rows. Further, all 
over the surface of the skin the mouths of sweat ducts may 
be found discharging the secretion from the sweat glands, 
which are situated in the deeper levels of the skin substance ; 
but wherever papillary ridges occur the sweat ducts 
invariably open on the summits of the ridges, and never by 
any chance into the bottom of the furrow which intervenes 
between two ridges. It seems to me that the constancy of 
this arrangement indicates a fundamental truth and cannot 
be regarded as a mere coincidence. As everyone knows, the 
skin contains the peripheral end-organs which are associated 
with the sense of touch. These touch-bodies are contained 
within a certain number of papille, and it has been 
