152 HARRIS HAWTHORNE WILDER. 



second has an "A -loop," the commonest form of hallucal pattern, 

 where the pattern is closed, except at the interval between the 

 great toe and the next, where the ridges run up and attain the 

 margin; the second area, II, has a proximal loop, probably with 

 triradius, which confines a part of the ridges. In the third formula 

 some of the ridges run in the form of a U between areas 2 and 3, 

 and in the fourth a similar union involves all the ridges of areas 

 I and 3. .The fifth notes an unusual form of hallucal pattern, 

 together with a strange mix-up in the union of areas, which will 

 become plain from the explanation of the rest. 



This method of formulating sole configuration is by no means 

 an ideal one, but it serves fairly well the general purpose of pic- 

 turing the configuration of a given sole in a few terms. A 

 fundamentally different method has been introduced by Schlagin- 

 haufen (1905), based upon the identity of the various triradii 

 occurring on the sole. Each one of these is designated by an 

 abbreviation, like "/Q" or "/I3," and the description is based 

 upon the position and relations of these. This method is thus a 

 method of description rather than a formulation, and although 

 in many ways convenient, it depends upon absolutely exact 

 homologies, which, in our present state of knowledge, is not pos- 

 sible. It thus seems better to rely upon some artificial method, 

 which is capable of picturing the essential details of a given 

 sole, rather than to attempt a series of homologies based upon 

 our present incomplete knowledge. 



The two proximal patterns, thenar and hypothenar, have 

 naturally suffered much displacement from the peculiar lengthen- 

 ing of the proximal part of the foot to form the human heel, and 

 a discussion of their position and homologies will be found farther 

 on in this article. Here it may be said that the transversely 

 placed loop, sometimes seen on the outer edge of the sole, just 

 proximal to the row of interdigital patterns across the ball, may 

 safely be considered the hypothenar pattern, or more probably 

 a portion of it (Fig. 7). The thenar, rare and more or less rudi- 

 mentary, as in the hand, is indicated by traces of irregularity in 

 the lines, or an occasional loop and triradius, found upon a slightly 

 raised area upon the inner edge of the sole, not much distal to the 

 heel (Figs. 21 and 23 below). 



