LUTHER BURBANK 



INBEEEDING FOE DEGENEEACY 



But lest too sweeping a conclusion be drawn 

 from this remarkable example of inbreeding for 

 genius, it is desirable that we should at once turn 

 to another royal pedigree and observe the effects 

 of inbreeding where the traits combined and ac- 

 centuated are not preponderantly desirable ones, 

 as in the case of Frederick the Great, but include 

 also elements of mental aberration and physical 

 and mental degeneracy. 



Such a pedigree is supplied in the immediate 

 ancestry of Don Carlos, the " madly depraved and 

 cruel" scion of the Spanish royal house, a man 

 who has been characterized as the most heartless 

 and depraved individual in modern history. 



A glance at a chart showing the ancestry of 

 Don Carlos reveals that his father, Philip II, and 

 his mother, Mary of Portugal, were at once first 

 and second cousins, and that each ancestral strain 

 leads quickly back to ancestors characterized as 

 weak or cruel or mad. 



Joana "the mad" appears twice in the third 

 generation, and the insane Isabella four times in 

 the fifth generation. 



The inbreeding is so close and intricate that 

 it would be difficult to characterize the relation- 

 ship. In five generations there are only twenty- 

 eight individuals instead of the normal sixty-two. 

 Thus a profoundly neurotic strain is allowed to 

 become overwhelmingly preponderant by repeti- 

 tion. As Dr. F. A. Woods has said, it was as if 



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