216 LETTERS TO DR. FLETCHER [CHAP. xix. 



Anyway I fear that Professor Riley has hardly a chance, 

 and indeed I wonder that he should contemplate changing 

 his grand central' position central to the whole world for 

 such a very inferior post without genial colleagues around 

 him. 



By book post accompanying I send a copy of Mons. J. 

 Danysz's paper on Ephestia (Flour moth), to your kind 

 acceptance, in case you have not yet seen it ; you will be 

 interested to run it over and see his views of Pyrethrutn. 

 I very much doubt whether we could get our millers to try 

 it, but it would be different with yon. 



