230 



Mr. E. Warren. 



Centroid = H'504888. p* = 12-483682. 



a = 3-533226. ^ = 1'936527. 



fn = 451-998740. 



fa = 0-001927. y3 2 = 2-900359. 



r = 55-546793. Skewness = 0*023589. 



The critical function 2y3 2 3^ 6 = 0-205063 is negative, and so 

 the theoretical curve has a limited range. This range is 53'325 ; in 

 the actual statistics it is 24, and so here as in the case of the* 

 R. antero-lateral it much exceeds any conceivable limit that may 

 exist for the crab. 



L. Dentary Margin. The trend and range of the mean resemble 

 those of the R. dentary. The total observed range of deviation is 

 417 524 thousandths. In groups 612 the range is 425 524, 

 giving 24 units. 



2 = 12-061035. 

 t = -4-649576. 



Centroid = 14-071229. 

 a = 3-472903. 



/i* = 438-990665. 



ft, = 0-012322. fa = 3-017770. 



r = 8438-070126. ' Skewness = 0-055527 



The critical function 2fa 3# 6 = 0'001426. From this 

 see that the theoretical curve has a limited range ; but this range 

 would be enormous, and the curve would closely resemble a normal 

 curve. 



Correlation of the Organs. Out of the six organs discussed, the 

 frequency curves of three of them (total breadth, frontal breadth, and 

 L. antero-lateral) give theoretical curves of unlimited range, while 

 the other three (R. antero-lateral, R. and L. dentary margins) give 

 curves of limited range. In every case the amount of skewness is 

 small, and the diagrams show that the generalised probability curves 

 do not give very obviously better fits than the normal curve. The 

 fact of the R. antero-lateral giving a strictly limited range while the 

 L. antero-lateral gives an unlimited one, demonstrates that little stress 

 can be placed upon the type of curve which a series of observations 

 may yield. 



In the present case the curves would appear to be sufficiently 

 normal to allow us to find Galton's function (known as r) for pairs of 

 organs. For this purpose we shall employ the modified formula 



2 Deviation A x Deviation B 



