38 FIFTY YEARS OF DARWINISM 



FRANCIS DARWIN ON THE TRANSMISSION OF 

 ACQUIRED CHARACTERS 



One of the most recent attempts to defend 

 the Lamarckian doctrine of the hereditary trans- 

 mission of acquired characters is contained in the 

 important Presidential Address of Mr. Francis 

 Darwin to the British Association at Dublin 

 (1908). In this interesting memoir the author 

 expresses the belief that such transmission is 

 implied by the persistence for unnumbered gene- 

 rations of the successive developmental stages 

 through w^hich the individual advances towards 

 maturity. Following Hering and Eichard Semon, 

 he is disposed to explain the hereditary trans- 

 mission of these stages by a process analogous 

 to memory. It is interesting to observe that 

 this very analogy had been brought before 

 Charles Darwin, but failed to satisfy him. He 

 wrote to G. J. Eomanes, May 29, 1876 :— 



' I send by this post an essay by Hackel attacking Pan. 

 and substituting a molecular hypothesis. If I understand 

 his views rightly, he would say that with a bird which 

 strengthened its wings by use, the formative protoplasm of 

 the strengthened parts became changed, and its molecular 

 vibrations consequently changed, and that these vibrations 

 are transmitted throughout the whole frame of the bird, and 

 affect the sexual elements in such a manner that the wings 

 of the offspring are developed in a like strengthened manner. 

 ... He lays much stress on inheritance being a form of 

 unconscious memory, but how far this is part of his molecular 

 vibration, I do not understand. His views make nothing 

 clearer to me ; but this may be my fault.' ' 



' More Letters, i. 364. See also the following sentence in a letter 



