THE HEREDITY OF RICHARD ROE. 12; 



are added together and divided by two. Half comes 

 from each side in the process of inheritance, but the 

 two halves are alike. But the personal peculiarities 

 recognisable in the father are different from those seen 

 in the mother. The son can not inherit all from both 

 sources. Certainly not more than half could come from 

 either source, for the new generation could not be built 

 of peculiarities alone. The old large, common heritage 

 must always have precedence. Galton has made a cal- 

 culation (referred to in the note above), based on wide 

 observations, that on the average 25 per cent of the 

 individual peculiarities are directly inherited from each 

 parent. On the average, each parent exerts the same 

 force of heredity. Half the characters come from each, 

 but in each half it would appear that about one half is 

 lost or rendered unrecognisable by other variation or by 

 contradictory blendings. The first division of qualities in 

 half is necessary and natural, for there are two parents. 

 The second division in half is an arbitrary assumption 

 which seems to find its warrant in Galton's studies. We 

 might assume without theoretical difficulty a third or a 

 fifth as being preserved intact among possible variations 

 and combinations. One half, however, seems nearer the 

 fact, and to find the fact is the only purpose of theory. 

 To the characters received from the parents we must 

 add the latent influence of grandparents, great-grand- 

 parents, and the long array of dead hands which, how- 

 I ever impotent, can never wholly let go. As the small- 

 est wave must go on, in theory at least, till it crosses 

 the ocean, so the influence of every ancestor must go on 

 to the end of the generation. Each of us must feel in a 

 degree the strength or weakness of each one of them. 

 To each grandparent Galton assigns 6| per cent. There 

 are four grandparents and two stages of generation sepa- 

 rate them from Richard Roe. Half the force of each, 

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