ACQUIRED CHARACTERS AND MUTATIONS 79 



The printed record of the family stops with the fifth gen- 

 eration, but out in the world, where the descendants of those 

 people continue to live and to multiply, the misfortune of 

 their fingers still goes on, and the number of those who 

 have this misfortune increases with each generation 



SMITH AND NORWELL'S CASE SHOWING POLYDACTYLISM 

 (From the " Treasury of Human Inheritance ") 



We see, then, that a character which begins as a mutation l 

 marches on through the generations without any regard to 



1 In 1885 Professor Hugo de Vries of Holland came upon an astonish- 

 ing primrose plant. It grew in a deserted potato field near Amsterdam, 

 and it had many unexpected descendants. Among these " some had few 

 branches instead of many ; some had small flowers instead of large ; some 

 had quite different leaves, and so on." Every now and then, also, a prim- 

 rose hybrid would have descendants quite like itself, and the new charac- 

 ters would go on from one generation to the next without change. A new 

 species had come unannounced into the field, and it was able to stay there 

 because it had descendants like itself. De Vries found many such cases 

 among his primrose plants, and it was he who first called them mutations. 

 The word is now used by all who study the laws of evolution. 



