78 NATURAL INHERITANCE. [CHAP. 



except where otherwise expressed. The factor I used 

 was 1'08, which is equivalent to adding a little less than 

 one-twelfth to each female height. It differs slightly 

 from the factors employed by other anthropologists, 

 who, moreover, differ a trifle between themselves ; any- 

 how, it suits my data better than 1'07 or T09. I can 

 say confidently that the final result is not of a kind to 

 be sensibly affected by these minute details, because it 

 happened that owing to a mistaken direction, the com- 

 puter to whom I first entrusted the figures used a 

 somewhat different factor, yet the final results came out 

 closely the same. These E.F.F. data have by no means 

 the precision of the observations to be spoken of in the 

 next paragraph. In many cases there remains consider- 

 able doubt whether the measurement refers to the height 

 with the shoes on or off; not a few of the entries are, I 

 fear, only estimates, and the heights are commonly given 

 only to the nearest inch. Still, speaking from a know- 

 ledge of many of the contributors, I am satisfied that a 

 fair share of these returns are undoubtedly careful and 

 thoroughly trustworthy, and as there is no sign or sus- 

 picion of bias, I have reason to place confidence in the 

 values of the Means that are derived from them. They 

 bear the internal tests that have been applied better 

 than might have been expected, and when checked by 

 the data described in the next paragraph, and cautiously 

 treated, they are very valuable. 



Special Data. A second set of data, distinguished 

 by the name of " Special observations," concern the 



