110 PROF. K. PEARSON ON THE MATHEMATICAL THEORY OF EVOLUTION. 
moments respectively, T notice the following values for the standard-deviation of 
“ Crabs No. 4,” as calculated from the second, fom'th, and sixth moments— 
0-2 = 274, 
0-4 = 277, 
cTg = 2'84. 
Practically, it would be difficult to say which of these results gives the best fitting 
theoretical curve. For statistics of this kind they are sensibly the same. Thus, till 
another method of attacking the problem of the resolution of asymmetrical frequency- 
curves is propounded, I think there is not sufficient evidence against the use of higher 
moments to lead us to discard a method based upon them as essentially likely to lead 
to large errors.—-K. P.] 
O J 
