Harris Hawthorne Wilder 425 



In his various works Galton has invented certain methods of study 

 and investigation, and has established certain fundamental principles 

 which are of application to the entire palmar and plantar surfaces, and 

 he may thus be considered, after Malpighi and Purkinje, a pioneer and 

 founder of the science here treated. His methods consist of various 

 practical ways of printing and interpreting the course of the papillary 

 ridges, and he has established two important principles; (1) that the 

 papillary ridges do not change from birth to death but remain abso- 

 lutely constant, even to the minutest details, and are capable of sur- 

 viving a considerable mechanical injury, and (3) that the individual 

 variation is so great that, even in the case of a single finger, there is 

 no practical likelihood of its pattern being exactly duplicated by that 

 of another individual, thus rendering these parts of the greatest value 

 as a means of personal identification. 



For several years past, since becoming interested in the preparation 

 of a short paper upon comparisons between the epidermic " centres of 

 disturbance " in the Primates and the pads of walking mammals (Anat. 

 Anz., Bd. XIII, No. 8, 9, 1897) I have been engaged in the attempt to 

 extend the work of Galton to the field left uninvestigated by him, 

 namely to the palmar surface of the hand and to the entire volar sur- 

 face of the foot, and I believe that the points thus far established are 

 of sufficient general interest to allow publication as a report of progress, 

 without waiting for more extended results which are dependent upon 

 the obtaining of a very large amount of material and which will con- 

 sume several years in elaboration. My method of studying the palms 

 and soles has been exclusively by means of prints taken off by a slight 

 variation of the method most favored by Galton; that of the use of 

 printers' ink, applied with a rubber roller such as is employed in print- 

 ing with the Edison mimeograph, and a moment's comparison of a real 

 palm with a good print of the same will convince one of the superior 

 utility of the latter. The only possible disadvantage is the reversal of 

 right and left sides in the print, a condition to which one becomes accus- 

 tomed as readily as to the reversal of the image in the compound 

 microscope. 



The main points of interest which have thus far resulted from the 

 investigation may be siimmarized under the three following heads, 

 which will be considered in order: (1) General morphology of the 

 PAPILLARY RIDGES OF BOTH PALMS AND SOLES; of interest both for 

 comparison with the condition seen in other Primates and as furnish- 

 ing a convenient source of material for the study of individual varia- 

 tion. (Whether these points will be found of ethnographic value in 

 the study of different races is a point yet to be determined.) (2) A 



