362 ORGANIC GROWTH sec. 



understand how in course of time such functions have 

 become localised, and have modified the structure of the parts 

 devoted to them more and more, as each generation inherited 

 the alteration produced in its predecessor. 



I will now add some further arguments concerning this ques- 

 tion, derived from a subject to which I have already referred. 



The Acquisition and Inheritance of Peculiarities of 

 Voice and Speech, and the Speech of Animals 



I have already opposed Weismann's argument against the 

 inheritance of acquired characters, which depends on the 

 assertion that neither the faculty of speaking nor of reading 

 is inherited. 



In one of his latest writings -^ he says : " When we ade- 

 quately realise how energetically and how uninterruptedly 

 we practise speaking throughout our whole lives, whether we 

 are speaking aloud, or thinking silently to ourselves, and 

 when we consider that in spite of this continual practice 

 which has been performed by all human brains and vocal 

 organs for centuries, the faculty of speech has not in the least 

 degree become established as a hereditary character, we shall 

 be inclined ever afterwards strongly to doubt that any 

 acquired characters in the true sense of the word can ever be 

 inherited." 



I have already remarked that we ought not to expect the 

 faculty of speech, or of reading, to be inherited, because these 

 are very complex accomplishments, not simple faculties of 

 the organism, which alone we bring with us into the world 

 at birth. 



Apart from the fact that the development of human speech 

 dates from a period geologically recent, we cannot argue about 

 its heredity from the length of time which has passed since 



^ TJeher den Riickschritt in der Natur (Retrogression in Nature). 



