CHAPTER X. 



ATAVISM. 







ATAVISM Or the law whereby latent forces 

 physical and mental characteristics peculiar to a 

 species, family or individual that have not been 

 manifested for one or more generations, become 

 active, thereby causing ancestral traits to reappear 

 in offspring. 



Atavism is defined by the distinguished psy- 

 chiatrist, D. Von Kraftebings, as the law by which 

 "the bodily and mental organization and charac- 

 ter can be transmitted from the first 'to the third 

 generation, without any necessity that the second 

 and intermediate one should exhibit the peculiar- 

 ities of the first." 



In natural history atavism is the reappearance 

 in animals or plants of traits belonging to their 

 remote progenitors that their immediate parents 

 did not possess. The term has been used by some 

 as synonymous with Darwin's "Reversion to type," 

 indicating in this connection not only the occa- Atavism in 

 sional or individual appearance of such remotely 

 descendant traits, but the actual returning to them 

 of a variety or species. "Domesticated animals," 

 Darwin observes, "if allowed to run wild become 

 nearly (though rarely exactly) like their wild an- 

 cestors." 



Atavism as applied to man has been studied 



