PALM AND SOLE STUDIES. 



149 



beneath the interval between this digit and the next, is the largest, 

 and is usually covered with a definite arrangement of ridges, the 

 hallucal pattern. It will be noted that this, the most important 

 of the four in the foot, is the same one that, in the hand, appears 

 only as an adjunct of the rare thenar pattern, and is thus of little 

 importance. This difference is plainly the result of the difference 

 in function and use of foot and hand, as in the former the main 

 work is performed by the heel, and by the four interdigital areas 

 placed in a row close together, while of this row the inner end, 

 below the great toe, is used the most. 



The descriptive formulation of the sole configuration is thus 



FIG. 8. Print of a right sole, showing a second case of the method of inter- 

 pretation used in the preceding figure. This print exhibits the unusual case of the 

 effacement of a definite hallucal pattern, similar to the sixth type 'shown in Fig. 9. 

 Formula: BC-L-Cl-Cl-x. 



seen to be most advantageously accomplished by using the areas 

 rather than the lines, and describing the condition of the patterns 

 found upon them. To begin with, the hallucal pattern, which is 

 used for the classification of soles into primary groups, is found 

 in its most primitive form as the whorl, equipped with its three 

 typical triradii, A, B, and C (Fig. 9). Either triradius may be 

 wanting, thus allowing the ridges to open, or gush out, to use a 



