MIRACLES OF SCIENCE 



yet available, it would be folly to say that we have 

 full data for directing the marriage of human beings. 

 But on the other hand, it is possible to draw some 

 very practical conclusions with regard to the subject 

 even now. The new science which Francis Galton 

 christened "Eugenics" is in its infancy, but its prog- 

 ress will be far more rapid than it could have been 

 had not the principles of Mendelian inheritance been 

 discovered. From the remotest times it has been 

 matter of familiar observation that both good and 

 bad qualities of parents are likely to be transmitted 

 to their offspring. The familiar saying that like 

 begets like, and various equally familiar Biblical 

 phrases about the sins of parents, illustrate the fact 

 that the general facts of heredity are common knowl- 

 edge. But the matter assumes a novel aspect in the 

 light of the new investigations. 



It had been taken for granted that the traits of two 

 parents tend to blend in their offspring, and that any 

 particular quality which was prominent in an indi- 

 vidual would presently become blended with other 

 qualities in his descendants. But the new studies of 

 heredity show that there are many characteristics of 

 both body and mind that do not tend thus to become 

 modified through blending, but which may seem 

 altogether to disappear in any given generation, or 

 even for successive generations, and yet re-appear 

 with full force in a remote descendant. In the words 

 of Professor Charles B. Davenport, "After a score of 

 generations the given characteristic may still appear 

 unaffected by the repeated unions of foreign germ 

 plasm." 



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