Harris Hawthorne Wilder , 435 



feet the testhnony of such a case as that shown in Figs. 10 and 11 

 alone seems a remarkable corroboration of the above theory, a point still 

 more emphasized by the equal correspondence in the three other ex- 

 tremities, the left hands and the feet. Out of my entire collection of 

 100 palm-prints (not including the twins) it may be possible to find one 

 or more cases where two hands bear a general correspondence in the 

 disposition of the main lines and areas, but a comparison of the other 

 hands and the feet of the two individuals would show the resemblance 

 to be a chance one and limited to the single extremity. In the case of 

 the three sets of identical twins, however, involving a comparison of 

 eleven pairs of prints (one foot-print is missing in one set), each case, 

 as seen by the six here given, shows almost the same degree of corre- 

 spondence, thus removing all chance of coincidence. It seems to me, 

 then, that we have in these comparisons a definite and tangible proof, 

 far more reliable than that of general facial resemblance, of the complete 

 physical identity of such cases and one tvhich can he accounted for only hy 

 the theory of origin from a single egg, the hereditary properties in which are 

 equally and exactly divided hy the first cleavage process. To ascertain 

 how these parts are related in the rare but actual cases of identical 

 triplets and quadruplets would be of the greatest importance. 



In one of the sets of twins I made also a careful comparison of the 

 finger tips and found that nine out of the ten sets of patterns cor- 

 responded exactly, while in the tenth case, that of the right index 

 finger, the two patterns were the exact symmetrical equivalent of one 

 another, a case which might suggest to a Weismannian the somewhat 

 fanciful idea of the mechanical reversal or other form of displacement 

 of a determinant. 



The completeness of identity in these cases is, however, not so great 

 but that, both in tlie finger tips and on the surface of the palms and 

 soles, there are differences sufficiently marlied to render impossible the 

 mistahing of one print for another. The identity is that of lines and 

 areas rather than that of separate ridges, and the interruptions, branch- 

 ings and other irregularities in these last, called by Galton the miniitire, 

 are entirely individual. Thus, notwithstanding the remarkable cor- 

 respondences in the case of identical twins, which are naturally greater 

 than could ever exist in any other two people, there are still enough 

 individual differences to distinguish them from one another. 



Concerning the fourth set of twins investigated, one in which there 

 is no great similarity in general appearance, and which, in accordance 

 with the above-mentioned theory, may be supposed to have been derived 

 from two separate eggs, it may be sufficient to state that there is also 



