ANTHROPOMETRIC LABORATORIES 253 



not yet " taken on," there was spare time for inquiry 

 into finger-prints. 



I described the results in the above-mentioned 

 lecture so far as they had then been obtained, and 

 subsequently in a more advanced shape in a memoir 

 read before the Royal Society in 1891 [116]. It 

 was argued in it that these patterns had a theoretical 

 significance, which has not, I think, even yet been 

 adequately appreciated, which bears on discontinuity 

 in evolution. I showed that the different classes of 

 patterns in finger-prints might be justly compared 

 to different genera. As, however, they had been 

 formed without any aid from natural selection, I 

 concluded that natural selection had no monopoly 

 in moulding genera, but that internal conditions 

 must be quite as important. 



I have always believed that the number of posi- 

 tions of stability in every genus must be limited, 

 from which moderate deviations, but not great ones, 

 are possible without causing destruction. There are 

 limits which, if they can be overpassed without 

 disaster, would require a new position of stability 

 in the organisation. Comparatively few intermediate 

 finger-patterns are found between a "loop" and a 

 " whorl," these representing two different and well- 

 marked genera or positions of stability. 



The modern division of views concerning the 

 immediate causes of evolution, whether it be due 

 to the slow accumulation of small factors or else by 

 the sudden mutations of de Vries, are paralleled by 

 those held by the physicists of the fifties on the 

 method by which a glacier adapts itself to its bed, just 

 as if it were a viscous body, which it certainly is not 



