LETTERS. 207 



He then wrote as follows : 



" April 11 118. "Down. 



" MY DEAR SIR, I should be very much obliged if you 

 could get some one to name the photographs of the enclosed 

 insect and read the enclosed letter. It seems a pretty, but I 

 think not new case of protective resemblance. One might 

 fancy that the large ocelli on the under wings were a sexual 

 ornament. Perhaps these photographs might be worth ex- 

 hibiting at the Entomolog. Soc. I do not want them returned 

 (unless indeed Dr. Zacharias wants them back, which is not 

 probable) or the enclosed letter. 



" A single word with the name of the genus and if possible 

 of the species, would suffice. 



" Pray forgive my troubling you and believe me 



" Yours faithfully, " CH. DARWIN. 



" I am glad that F. Miiller's letter interested you. He has 

 published a paper with plates on the shape of the hairs or 

 scales on the odoriferous glands of many butterflies, which 

 I could send you, but I doubt whether you would care for it." 



Darwin then sent another letter from Fritz 

 Miiller containing some interesting notes on odori- 

 ferous organs in butterflies, and on the occasional 

 failure of the female insect to deposit her eggs on 

 a plant which can serve as the food of the young 

 larvae. The beetles alluded to were a species of 

 Spermophagus. The two letters printed below refer 

 to the same subjects : 



" May 15 [1878]. " Down. 



" MY DEAR SIR, I think the enclosed will interest you. 

 The letter to me need not be returned as I have had the only 

 important passage for my work copied out. In the letter F. M. 

 [Fritz Miiller] sent me seeds of Cassia neglecta and several 

 beetles arrived alive, having formed their cocoons, and gnawed 



