Personal Identification and Description 



203 



terminal groups) about a group containing 4£ ridges on the average. Each 

 of these groups would contain 40 to 50 individuals of the 156, or less than 

 \ and more than \ of the whole. Hence to count ridges in the first finger 

 presenting a loop would reduce to less than a frequency of 10 all the groups 

 of large frequencies except those under the formulae ull, ull, 11, 11 and www, 

 www, ww, ww (see the table on our p. 200). For the former group Galton 

 suggests in addition counting ridges on the middle finger, and is thus able to 

 break up his material into groups of less than 10 sets*. Here he introduces an 

 interesting point; he gives a partial table (p. 82) for the number of ridges 

 which occur in right middle and ring fingers for certain values of the 

 count on the right forefinger. If the means of the former be found we 

 have : 



This suggests that there is correlation between the number of ridges at 

 any rate in the fore and middle fingers of the same hand, and indicates 

 a possible line of inquiry for the inheritance of ridge-numbers, when loops 

 are available in both relatives. 



We have next to consider how Galton meets the difficulty of the www, 

 www, ww, ww class of pattern and others with numerous whorls. The main 

 idea he uses is that if the tail of a whorl or the ridges which form it come 

 from the radial side, the subscript or suffix r is used. If they come from the 

 ulnar side the suffix u might be used, but Galton says this is so frequent 

 that he does not use it. Hence w standing alone might mean fed from 

 both sides, from neither side, or from the ulnar side. The suffix s is, 

 however, used for whorls fed from both sides, but this may occur in three 

 different ways: 



(i) The ridges from either side may double back upon themselves, so that 

 the contributory portions have blunt ends = sb. 



(ii) The ridges from the two sides may be twisted together almost to 

 a point = sq. 



(iii) One set of contributory ridges may spring normally from one side of 

 the finger, the other 'from one side of the tail of a tailed whorl = sv. 



There are other symbols used by Galton in relation to whorls, namely g, 



* The reader must remember that these numbers are based on a standard of 1000 sets. 

 100,000 sets some of the groups might still be too large. 



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For 



