ACQUIRED CHARACTERS 67 



Perhaps the question, as Montgomery has suggested, 

 ought to be changed to read: "What kinds of acquired 

 characters are inherited?" It is obvious that discus- 

 sion is futile until a common denominator in the shape 

 of a definition of acquired characters shall be accepted. 



6. WEISMANN'S CONCEPTION OF ACQUIRED 

 CHARACTERS 



Weismann defines an acquired character as any 

 somatic modification that does not have its origm in 

 the germplasm. 



Of course those somatic modifications which are 

 phases of the developing individual, such as the 

 acquisition of a deeper voice at puberty or the substi- 

 tution of the permanent dentition for the milk-teeth, 

 are somatic variations which have their rise and con- 

 trol in the germplasm and consequently cannot prop- 

 erly be included under the head of acquired characters. 



Examples of acquired characters in the Weisman- 

 nian sense are mutilations, the effects of environment, 

 the results of function as in the use or disuse of certain 

 organs, and such diseases as may be due either to in- 

 vading bacteria or to the neglect or abuse of the bodily 

 mechanism. 



7. THE DISTINCTION BETWEEN GERMINAL AND 

 SOMATIC CHARACTERS 



Redfield has thrown light on the classification of 

 the characters which make up the individual by quot- 

 ing the familiar lines: 



