CHAPTER III 

 THE INHERITANCE OF ACQUIRED CHARACTERS 



The inheritance of acquired characters has been 

 mentioned in its relation to Weismann's theory of 

 germinal continuity, but it deserves a somewhat fuller 

 consideration. The idea was first developed by Lamarck 

 in connection with his theory of evolution, the so-called 

 theory of appetency, or the effect of use and disuse. 

 Francis Galton, in 1875, was one of the first to express 

 skepticism in regard to such inheritance, but it was 

 Weismann who was most influential in combating the 

 idea. After Weismann's presentation of the situation, 

 biologists were divided into two camps in reference 

 to the inheritance of acquired characters: (i) neo- 

 Lamarckians, who affirm belief in the inheritance of 

 acquired characters, and (2) neo-Darwinians, who deny 

 it. Geneticists and embryologists, however, whose work 

 brings them most in contact with the problem, seem to 

 be fairly well agreed that acquired characters are not 

 inherited. 



Much of the lack of agreement in this controversy 

 is due to the definition of an acquired character. It 

 should be kept in mind that actual characters are not 

 inherited, but only the determiners, which regulate the 

 way in which the organism reacts to its environment. 

 For example, when it is said that a child inherits its 

 father's nose, the statement is not meant to be literally 

 true; it is meant that just as there was something in 



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