CHAPTER VIII. 



DISCUSSION OF THE DATA OF EYE COLOUR. 



Preliminary Kemarks. — Data. — Persistence of Eye-Colour in the Popula- 

 tion. — Fundamental Eye-Colours. — Principles of Calculation. — Results. 



Preliminary Remarks. — In this chapter I will test 

 the conclusions respecting stature by an examination 

 into hereditary Eye-colour. Supposing all female 

 measures to have been transmuted to their male equi- 

 valents, it has been shown (l) that the possession of 

 each unit of peculiarity of stature in a man [that is of 

 each unit of difference from the average of his race] 

 when the man's ancestry is unknown, implies the exist- 

 ence on an average of just one-third of a unit of that 

 peculiarity in his "Mid-Parent," and consequently of 

 the same amount in each of his parents ; also just one- 

 third of a unit in his Son ; (2) that each unit of pecu- 

 liarity in each ancestor taken singly, is reduced in 

 transmission according to the following average scale ; — 

 a Parent transmits only J, and a Grand-Parent only J^. 

 Stature and Eye-colour are not only different as 

 qualities, but they are more contrasted in hereditary 



