238 LETTERS TO DR. SCHOYEN [CHAP. xxi. 



time to time copies of your valuable pamphlets, and also of 

 your portrait, which I have much pleasure in adding to my 

 collection of portraits of the leading entomologists of the 

 world. But I trust you will forgive my long silence 

 because for a long time (that is, since last autumn) until 

 about three weeks ago, I have been a great sufferer, and it 

 has been with difficulty I have been able to keep up to work. 



May I ask your kind acceptance of my fifteenth Report (ac- 

 companying by book post), and a little brochure I recently 

 arranged by special request ; also with them may I place a 

 copy of my portrait, recently taken, in your hands ? I value 

 your pamphlets which you kindly send me, much ; but, 

 unfortunately, I have never been able to master your 

 language so when I have read the title, if it be a subject 

 bearing specially on my own work, I get help from a 

 linguist to enable me to benefit. Trusting that for the 

 reasons given you will pardon my long silence. 



October 25, 1893. 



I thank you very much for being so good as to tell me of 

 the appearance of the Cecidomyia destructor (Hessian fly, fig. 

 15) in Norway. This observation of the further spread of this 

 troublesome barley pest is very interesting to me, and I am 

 also greatly obliged to you for letting me have the charac- 

 teristic specimens of puparia. There is no doubt that these 

 are the chrysalis cases (the "flax-seeds," as we call them 

 here) of the Hessian fly. I at once wrote to two friends to 

 endeavour to procure the specimens you name, and it 

 would have been a great pleasure to me to send them at 

 once, but I much doubt whether 1 shall be able to procure 

 any of the Wheat midge, C. tritici ; I have not got any my- 

 self, nor have my two colleagues so far as they see. 



About the Hessian fly, I have been more successful. I 

 have secured some specimens well put up for the micros- 

 cope. It is too late this evening to repack them properly, 

 but I hope to send you three slides to-morrow in a 

 registered letter, of which, with very great pleasure, I beg 

 your kind acceptance. Should they not reach you in 

 proper condition, you will oblige me by letting me know, 

 that I may try to replace them. I should hope that the 

 thoroughly well-advised treatment which you are 

 endeavouring to get carried out in the infested district 

 will be successful. I have great confidence in the efficacy 

 of destroying the puparia in the screenings or siftings ; and 

 ploughing so as to turn down the "flax-seeds" also quite 

 certainly answers well. 



