Harris Hawthorne Wilder 



455 



of the formative force determining the areas but allowing their relative extent 

 to be determined by the stress of growth at the different points, the two left 

 soles have been reproduced here, covered by their lines of interpretation 

 (Fig. 11). In these it will be noted that of the main lines. D fuses with the 

 lower triradius: C curves inwards and opens between digits III and IV 

 (or their corresponding triradii) ; B curves outward, embracing C and open- 

 ing between the triradii of digits IV and V; while A differs slightly in the two 

 individuals, fusing with the lower triradius in x and missing it by three 

 ridges in y. This is the only difference in the main pattern in the two soles 

 and may easily be attributed to a slight difference in the ridges, since their 

 courses lie at one point so near one another. The hallucal line at the base 



Fig. 11. Prints of the left soles of twins No. II. Natural size. The lines of interpreta- 

 tion are marked with India ink. 



Of the hallux forms a spiral core for the hallucal, or 1st interdigital pattern, 

 the general configuration of which is marked by the dotted lines. Both 

 in this case and in that of the other pattern, the 3rd interdigital, the 

 ridges picked out by the dotted lines are taken arbitrarily, as the only pur- 

 pose is to show the general trend of the ridges in the region thus marked, 

 and thus no special significance should be attached to their total number 

 in either case. The five dotted lines defining the hallucal pattern of x, 

 for example, as compared with the three (or four) in y mean nothing more 

 than, perhaps, a slightly greater width to be defined in the latter case, and 

 the two that happen to be used in each case to define the loop in the 3rd 

 interdigital area are intended to point out the identity in shape in the two 

 patterns, with no reference to the number of ridges involved. 



III. Tracings of this entire set have been already published in the American 

 Journal of Anatomy, Vol. I, p. 437, and exhibit again the same principles as 



