VII] Law of Ancestral Heredity 131 



the sole, line of descent runs from germ to germ and not 

 from person to person The person may be accepted on 

 the whole as a fair representative of the germ, and being so, 

 the statistical laws which apply to the persons would apply 

 to the germs also, though with less precision in individual 

 cases. Now this law is strictly consonant with the observed 

 binary subdivisions of the germ cells, and the concomitant 

 extrusion and loss of one-half of the several contributions 

 from each of the two parents to the germ-cell of the off- 

 sprmg. The apparent artificiality of the law ceases on these 

 grounds to afford cause for doubt ; its close agreement with 

 physiological phenomena ought to give a prejudice \n favour 

 of its truth rather than the contrary." 



Had segregation been known to Mr Galton the Law of 

 Ancestral Heredity would not have been promulgated. 

 It is obvious that so soon as that phenomenon is recog- 

 nized and appreciated, all question of useful or direct 

 applicability of the Law of Ancestral Heredity is at an end. 

 That method of representing the phenomena of Heredity 

 and all modifications of it are based on the false assumption 

 that any individual can transmit the characteristics, of any 

 ancestor, and especially of any recent ancestor. When this 

 conception was shown to be untrue, the structure which the 

 biometricians have offered to the world as a scientific study 

 of Heredity ceased to have meaning or value. Statistical 

 examination of ancestral composition may, as we have seen, 

 occasionally give a prediction in good correspondence with 

 fact, but this is due to coincidence and not to any elements 

 of truth in the ratiocination by which the prediction was 

 reached. 



As an attempt to compass the solution of an intricate 

 problem by labour and ingenuity without proper data or 

 equipment Mr Galton's work deserves long to be remem- 

 bered. It stands out as a significant and stimulating event 

 in the history of biology. 



9—2 



