1865.] FRITZ MULLER. 37 



will be quizzed for it by some of your friends as too 

 exaggerated. 



[The following letter refers to Fritz Mtiller's book, 'Fur 

 Darwin,' which was afterwards translated, at my father's 

 suggestion, by Mr. Dallas. It is of interest as being the 

 first of the long series of letters which my father wrote to 

 this distinguished naturalist. They never met, but the 

 correspondence with M tiller, which continued to the close of 

 my father's life, was a source of very great pleasure to him. 

 My impression is that of all his unseen friends Fritz Miiller 

 was the one for whom he had the strongest regard. Fritz 

 Miiller is the brother of another distinguished man, the late 

 Hermann Miiller, the author of ' Die Befruchtung der Blumen,' 

 and of much other valuable work :] 



C. Darwin to F. Miiller. 



Down, August 10 [1865]. 



My dear Sir, — I have been for a long time so ill that I 

 have only just finished hearing read aloud your work on 

 species. And now you must permit me to thank you 

 cordially for the great interest with which I have read it. 

 You have done admirable service in the cause in which we 

 both believe. Many of your arguments seem to me excellent, 

 and many of your facts wonderful. Of the latter, nothing has 

 surprised me so much as the two forms of males. I have 

 lately investigated the cases of dimorphic plants, and I should 

 much like to send you one or two of my papers if I knew 

 how. I did send lately by post a paper on climbing plants, 

 as an experiment to see whether it would reach you. One of 

 the points which has struck me most in your paper is that on 

 the differences in the air-breathing apparatus of the several 

 forms. This subject appeared to me very important when I 

 formerly considered the electric apparatus of fishes. Your 



