PALM AND SOLE STUDIES. 



IX. THE MORPHOLOGY OF THE HYPOTHENAR OF THE HAND; 

 A STUDY IN THE VARIATION AND DEGENERATION 

 OF A TYPICAL PATTERN. 



HARRIS H. WILDER. 



Basing our conclusions upon the results of morphological ob- 

 servation, mainly those of Miss Whipple, 1904, it is safe to assume 

 that a friction-skin pattern, whether a "finger-print," i.e., one 

 taken from the apical mound of a finger, or one located upon the 

 broader surface of either palm or sole, has its origin in a raised 

 conical mound, surrounded by an encircling duplicature of skin 

 (Fig. i). This assemblage of parts becomes covered by series 



(a) 



upper 

 trlradiu 



(b) 



outer tri radius 



(c) lower trl radius 



FIG. i. Diagrams of a pad, and its enclosing folds showing apex, 

 concentric circles and triradii. 

 Above Profile view. 

 Below Ground plan of same. 



of epidermic ridges, themselves composed of rows of single 

 units, probably the morphological equivalents of scales, which 

 in their configuration are influenced by the underlying details. 

 The encircling folds develop as similar ridges which follow the 

 edges, and the two, three, or four points where different folds 

 meet each other form triangular fields, or often triradiate lines 

 diverging from centers, the entire system of which precisely 



393 



