248 LETTERS TO DR. NALEPA [CHAP. xxi. 



hands. This is a very great favour, and you may rest 

 assured that I will most fully acknowledge my debt to your- 

 self. From the study of the pamphlet which you were good 

 enough to send me I have already benefited largely. But I 

 earnestly pray you, do not let me intrude on your kind 

 liberality for any work that I might be able (if you were 

 good enough to give me the name) to purchase. My 

 London booksellers are accustomed to procuring Conti- 

 nental publications for me, and I am feeling myself so 

 greatly indebted to you for valuable information that I am 

 quite uneasy at not being able to reciprocate as I much 

 wish. I have delayed writing in the hope of being able to 

 procure some specimens, but as yet I have only the enclosed 

 (Pear-leaf blister galls, ? of Phytoptus pyri) to send to you 

 from trees in my own garden, and these I am afraid will be 

 of little interest. Your valuable list of infestations has shown 

 me that there are very many kinds of Phytoptus attack that 

 I had no idea of the existence of, and I will indeed try to 

 be of some service to you. 



By book post accompanying I beg your kind acceptance 

 of the current number of my Annual Report, in which are 

 some remarks on a species of Entedon (or Entedonidce, para- 

 sites of Dipterous leaf-miners especially) which we found in 

 currant buds in watching for what we hoped might prove a 

 parasite on the Phytoptus. I fear my report will be of little 

 interest to you, but I just beg you to accept to show the 

 kind of publication. 



August 16, 1893. 



I postponed replying to your kind letter of the yth in the 

 hope that I might have something of interest to send you, 

 but I have only been able to procure the enclosed Prunus 

 galls. They are from Toddington, Gloucestershire. I 

 rather fear they will wither on the journey, but I forward 

 them because the twigs have something amiss with them, 

 which just possibly may be owing to Phytoptus presence. 

 Thank you much for giving me the name of the Phytoptns 

 pyri, which I have noted at p. 296 in your " Katalog," which 

 you were good enough to send me, and which is of truly 

 valuable assistance. My booksellers will, I hope, before 

 long procure me five or six of your publications either in 

 separate impressions or in the parts or volumes in which 

 they were published, and then I shall hope to have the 

 information that I am much wishing for, without troubling 

 you personally. But should the special attack, which I 

 desire to understand better, not be specifically described, 



