LUTHER BURBANK 



AID FROM GALTON *S LAW 



In point of fact, it is necessary, in order to 

 gain a clear understanding of the matter, to sup- 

 plement what was just said about the multiple 

 ancestry of each individual with the explicit state- 

 ment that the major part of the qualities that are 

 likely to find expression in any given case has 

 been tangible in the immediate ancestors. 



According to an estimate made by the late Sir 

 Francis Galton, and hence sometimes spoken of 

 as Galton 's law, each individual inherits half his 

 tangible traits from his parents, one-quarter from 

 his grandparents, one-eighth from the great- 

 grandparents, and so on in decreasing ratio. 



In accordance with this rule, it is clear that 

 only a very small portion of the tangible traits of 

 any individual will have been inherited statistic- 

 ally from ancestors more remote than the great- 

 grandparents. So in practice we are fully justi- 

 fied in saying that a person whose immediate an- 

 cestors are known to show a preponderance of 

 undesirable traits has bad heredity, even though 

 it can be shown that there were persons of the 

 most commendable character among his remote 

 ancestors. 



In practice, then, it is possible for Mr. Bur- 

 bank to determine pretty accurately what will be 

 the main characteristics of the progeny of any 

 given cross from observation of the parents and 

 grandparents alone ; yet it must never be forgot- 

 ten that as regards some quality that may be 



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