xxiv] SIR CHARLES LYELL 423 



acquired characters ; and further, when he showed that the 

 supposed transmission of such characters, which Darwin had 

 accepted and which the hypothesis of pangenesis was con- 

 structed to account for, was not really proved by any evidence 

 whatever ; — I was compelled to discard Darwin's view in 

 favour of that of Weismann, which is now almost everywhere 

 accepted as being the most probable, as well as being the 

 most in accordance with all the facts and phenomena of 

 heredity. 



Towards the end of the year Sir Charles sent me a 

 number of interesting papers to read, and among them was 

 a criticism of Darwin by G. H. Lewes. When writing to 

 thank him for them I replied to this criticism as follows : — 



" I have just been looking through Lewes. I think that 

 in his great argument about the luminous and electric animals 

 he completely fails to see their true bearing. He admits the 

 fact that the organs producing light or electricity differ in 

 position and form whenever the animals that bear them differ 

 in general structure, while in their essential minute structure 

 the (corresponding) organs closely resemble each other, how- 

 ever widely the animals may differ. But this is a necessary 

 consequence of such organs being modifications of muscular 

 tissue, which is almost identical in structure throughout the 

 animal kingdom. If electrical and luminous organs were always 

 identical inform and position as well as in structure, it would 

 be a powerful argument in his favour ; but as it is, I do not 

 see that it proves anything but that the required special 

 variation of an (almost) identical tissue occurs very rarely, 

 and has still more rarely occurred at a time and under con- 

 ditions which rendered its accumulation useful to the animal, 

 in which case alone it would be selected and specialized so 

 as to form a perfect electric or luminous organ. 



"Again, to suppose that because one single organ of a 

 simple kind may be produced independently of common 

 descent, therefore a combination of hundreds of organs, many 

 of them consisting of hundreds of parts, should all be brought 

 by the action of similar causes to an identity of form, position, 

 and function (in different animals), appears to me absolutely 



