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THE PEESIDENT'S ADDRESS. 



Ladies and Gentlemen, 



You have already heard in the Report of the Council 

 all details connected with the working of our Society during 

 the past year, and taking into consideration the effects, direct 

 and indirect, of the war, we shall, I think, all agree that the 

 position of the Society is satisfactory. 



I shall not therefore detain you with any preliminary 

 observations, but proceed at once to the subject of my 

 address. 



Convergent Development among certain 

 Ectoparasites. 



In submitting a few notes to the Fellows of The Entomo- 

 logical Society of London on some aspects of parasitism, I 

 may possibly be excused for offering a word of explanation 

 as to why this theme was selected. 



Both fleas and bed-bugs have been of great interest to 

 me for a long time, and my knowledge of these groups 

 suggested that some attempt to put together a few observa- 

 tions concerning certain modifications in the structure of 

 Ectoparasites,- occurring repeatedly in those orders or families 

 which are wholly or partially parasitic, might prove of interest 

 to my audience this evening. 



My two friends, Dr. K. Jordan of the Tring Museum, and 

 the Rev. James Waterston, of the Imperial Bureau of Ento- 

 mology, have been good enough to supply me with informa- 

 tion concerning those parasitic insects about which I know 

 little or nothing, and Mr. Hugh Scott of Cambridge has like- 

 wise placed his great knowledge of the Nycteribiidae at my 

 disposal, and it must therefore be understood that many of 



