358 BOTANY [CHAP. XI 



Letter 681 has been in England two or three months, and is now going 

 to tour over the Continent to see all the zoologists. We liked 

 him very much. He is a great admirer of yours, and he tells 

 me that your correspondence and book first made him believe 

 in evolution. This must have been a great blow to his father, 

 who, as he tells me, is very well, and so vigorous that he can 

 work twice as long as he (the son) can. 



Dr. Meyer has sent me his translation of Wallace's Malay 

 Archipelago^ which is a valuable work; and as I have no use 

 for the translation, I will this day forward it to you by post, 

 but, to save postage, via England. 



Letter 682 To F. Mtiller. 



Down, May I2th [1870]. 



I thank you for your two letters of December I5th and 

 March 29th, both abounding with curious facts. I have been 

 particularly glad to hear in your last about the Eschsckoltzia ; 1 

 for I am now rearing crossed and self-fertilised plants, in 

 antagonism to each other, from your semi-sterile plants, so 

 that I may compare this comparative growth with that of the 

 offspring of English fertile plants. I have forwarded your 

 postcript about Passifiora> with the seeds, to Mr. Farrer, who 

 I am sure will be greatly obliged to you ; the turning up of 

 the pendant flower plainly indicates some adaptation. When 

 I next go to London I will take up the specimens of butter- 

 flies, and show them to Mr. Butler, of the British Museum, 

 who is a learned lepidopterist and interested on the subject. 

 This reminds me to ask you whether you received my letter 

 [asking] about the ticking butterfly, described at p. 33 of my 

 Journal of Researches ; 2 viz., whether the sound is in any way 

 sexual ? Perhaps the species does not inhabit your island. 



The case described in your last letter of the trimorphic 

 monocotyledon Pontederia* is grand. I wonder whether I 

 shall ever have time to recur to this subject ; I hope I may, 

 for I have a good deal of unpublished material. 



1 See Letter 677. 



2 Papilio /crania, a Brazilian species capable of making " a clicking 

 noise, similar to that produced by a toothed wheel passing under a 

 spring catch."- Journal, 1879, p. 34. 



3 This case interested Darwin as the only instance of heterostylism 

 in Monocotyledons. See Forms of Flowers, Ed. II., p. 183. F. M tiller's 

 paper is in the Jenaische Zeitschrift, 1871. 



