52 POPULAR SCIENCE MONTHLY. 



That the method of employing the prints of the apical patterns in 

 identification, as advocated by Galton is, in the hands of an expert, an 

 exact one, there can be no doubt, and it has been already accepted by the 

 English government and introduced in the province of Bengal and a 

 few other places, proving a dangerous rival to the more obvious but 

 less accurate system of Bertillon, which depends upon various physical 

 measurements; but the disadvantages occurring from the minuteness 

 of the parts upon which the observation depends and the necessity of 

 a lens, obstacles which would demand in all cases the employment of 

 a trained expert, would necessarily limit the application of such a 

 system to a few places where adequate means could be furnished. 



As a practical extension of the Galtonian system ; one in which the 

 minute details of the apical patterns are replaced by larger and more 

 definite markings, the present author advocates the use of prints, not 

 only of the ivliole palms, but of the soles as well, a system in which in 

 the vast majority of cases the cursory study of the main lines and areas 

 alone would be sufficient, while only in the almost impossible case of 

 general correspondence in the markings of two individuals in all four 

 members would resort to what Galton terms the 'minutiae' be necessary. 

 In the collection of one hundred palm prints alluded to above, there are 

 but two or three cases where the general formula is the same in the 

 hands of the same side, and in these the other hands and the two sets 

 of soles are widely different. If this should prove to be about the 

 usual average, then an identity of general plan, that is a similar course 

 in the four primary lines, may be expected to occur once in every 25 left 

 hands. Continuing this line of reasoning, the chance of the coincidence 

 being repeated in the right hand would be but 25 2 , or 625, and if the 

 same figures be true of the soles, then in complete sets the chance of 

 correspondence in the gross details would be 25 4 , or once in 390,625 

 times. But such 'identity' is by no means a complete one and really 

 means, not an identity at all but a general similarity in the course of the 

 four primary lines and in the areas defined by them. If such very 

 obvious details as the occurrence of patterns, or the condition of the 

 carpal area be also taken into account the chance of coincidence would 

 be many times decreased. Furthermore, as Galton has conclusively 

 proved by careful statistical study of the apical patterns, even in those 

 identical in general plan, the 'minutiae,' that is, the disposition, number 

 and length of the ridges forming the patterns are always very different. 



Aside from this, another line of proof of the impossibility of 

 complete duplicates is furnished by an examination of the hands and 

 palms of so-called 'identical' twins, or twins which are of the same 

 sex and otherwise closely resembling one another. In such cases we 

 have a strong biological warrant to expect a closer resemblance in these 



