ch. viii.] DISCUSSION OF THE DATA OF EYE COLOUR. 139 



behaviour than perhaps any other common qualities. 

 Parents of different Statures usually transmit a blended 

 heritage to their children, but parents of different Eye- 

 colours usually transmit an alternative heritage. If one 

 parent is as much taller than the average of his or her 

 sex as the other parent is shorter, the Statures of their 

 children will be distributed, as we have already seen, in 

 nearly the same way as if the parents had both been 

 of medium height. But if one parent has a light Eye- 

 colour and the other a dark Eye-colour, some of the 

 children will, as a rule, be light and the rest dark ; they 

 will seldom be medium eye- coloured, like the children 

 of medium eye-coloured parents. The blending in 

 Stature is due to its being the aggregate of the quasi- 

 independent inheritances of many separate parts, while 

 Eye-colour appears to be much less various in its 

 origin. If notwithstanding this two-fold difference 

 between the qualities of Stature and Eye-colour, the 

 shares of hereditary contribution from the various 

 ancestors are alike in the two cases, as I shall show that 

 they are, we may with some confidence expect that the 

 law by which those hereditary contributions are found 

 to be governed, may be widely, and perhaps universally 

 applicable. 



Data. — My data for hereditary Eye-colour are drawn 

 from the same collection of "Kecords of Family 

 Faculties" ("E.F.F.") as those upon which the inquiries 

 into hereditary Stature were principally based. I have 

 analysed the general value of these data in respect to 



