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PROFESSOR K. PEARSON AND MR. L. N. G. FILON 



distribution of the various numbers of glands occurring on a leg from 1 to 10""". 

 This curve is drawn from the right female leg only ; the curve for the other legs 

 would be very similar. We shall speak in a moment of the method of construction 

 of these curves ; but we want now to call attention to the fairly close similarity of 

 the two curves that gained by observation and the theoretical one a similarity 

 so close that we are justified in concluding that the law of distribution of the 

 variants in the leg glands of swine is the same as that of accidental errors." 



+.TC 



Now, in our opinion, the curve was markedly skew, and it seemed to us that most 

 interesting properties bearing on the action of selection on the Milllerian glands in 

 swine actually depended on this skewness. We have taken the distribution of 

 glands for 2,000 ? swine. 



To illustrate the difficulty of applying the normal curve we may remark that it 



gives about 6 swine per mille with 1 gland, and about 1 '5 with 2 glands, while 







* The aatliors have forgotten that there is a sensible percentage of zero-glands. 



