vii.] DISCUSSION OF THE DATA OF STATURE. 117 



Mid-Parents. This system had of course the same M 

 as the general Population, but its Q was reduced to 

 ^ x 17 inch, or to 1 "2 inch. It was next found 

 when the Statures of the Mid-Parents, expressed in the 

 form of P + (drD), were sorted into groups in which 

 D was the same (reckoning to the nearest inch), that a 

 Co-fraternity sprang from each group, and that its M 

 had the value of P + (±fD). The system in which 

 each element is a Mid-Co-Fraternity, must have the 

 same M as before, of 68^ inches, but its Q will be again 

 reduced, namely from 1 '2 inch to f x 1 "2 inch, or to 

 0*8 inch. Lastly, the individual Co-Fraternals were 

 seen to be dispersed from their respective Mid-Co- 

 Fraternities, with a Q equal in each case to 1'5 inch. 

 The sum of all of the Co-Fraternals forms the Popula- 

 tion of Generation II. Consequently the members of 

 Generation II. constitute a system that has an IV! of 

 68^ inches and a Q equal to </ [(0-8) 2 + (1'5) 2 ], = 17 

 inch. These values are identical with those in Genera- 

 tion I. ; so the cause of their statistical similarity is 

 tracked out. 



There ought to be no misunderstanding as to the 

 character of the evidence or of the reasoning upon 

 which this analysis is based. A small but fair sample 

 of the Population in two successive Generations has been 

 taken, and its conditions as regards Stature have been 

 strictly discussed. It was found that the distribution 

 of Stature was sufficiently Normal to justify our ignoring 

 any shortcomings in that respect. The transmutation 



