422 
Association of Finger-Prints 
nomenclature as far as they are required, and these follow in general those of 
Galton. Secondary classification with its minute details is not used in this paper. 
The four classes referred to above are Arches, Loops, Whorls and Composites. 
In Arches the ridges run from side to side, consecutive ridges being roughly 
parallel and the curvature increasing in general from the base to the tip. 
(Plate XX. Fig. i.) 
In Loops some of the ridges are doubled back upon themselves making a half 
turn or a little more, the two parts of the doubled ridge diverging from each other 
at the centre of the pattern. (Fig. ii.) Consequently this pattern has an open 
mouth directed downwards either towards the right or towards the left of the 
finger. The direction of this opening supplies a means of subdividing Loops into 
Radial and Ulnar Loops according as the direction is towards the radius or towards 
the ulna, that is, towards or away from the thumb. As will be seen later (p. 422b) 
the proportion of Radial Loops is very small except in the forefinger, so that this 
method of subdivision has been used only in dealing with that finger. 
In Whorls some of the ridges make a complete circuit, either as closed con- 
centric ovals or as a more or less continuous ridge forming a spiral. (Fig. iii.) 
Composites consist of combinations of two or more of the other patterns. 
(Fig. iv.) In this class are also included those finger-prints which are too irregular 
in general outline to be placed in any one of the other main groups. 
This class also includes the bulk of those patterns aboutwhich Sir Francis Galton, 
in his book on Fivger Prints*, p. 79, states — " They are as much Loops as Whorls, 
and properly ought to be relegated to a fourth class." It is possible, however, 
that some of Galton's " ambiguous cases " may have been classed in this paper 
with Loops. 
For further details of these principal classes with their modifications and sub- 
divisions reference may be made to the works mentioned in the footnotes on 
p. 421. 
3. Material. The material on which this investigation is based consists of 
two thousand complete sets of finger-prints of adult males, part of a much longer 
series in the Biometric Laboratory of University College, London. They belong 
to the lower type of artisan and labouring classes. No selection whatever has been 
made, except that a few sets, which were incomplete or which contained prints so 
damaged as to be indecipherable, have been rejected. 
4. Symbols. The following symbols are used : — A = Arch, SL = Small Loop ; 
ii^ = Large Loop (see p. 423); IT = Whorl; C = Composite ; Radial Loop; 
Lu = Ulnar Loop ; R = Right Hand ; L = Left Hand. R^, R^, R3, R^, R5 designate 
the thumb, forefinger, middle, ring and little finger respectively of the right hand, 
and Li, L^, L^, L^, represent the corresponding fingers of the left hand. 
* Finger Prints, by Francis Galton, F.E.S., Macmillan, 1892. 
