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Mr. Edward Saunders on 



possess some special defence, perhaps by means of a secre- 

 tion, or the juices of the body. It is difficult otherwise to 

 account for the dominant central species of mimetic 

 groups being composed even temporarily of males, to the 

 almost complete exclusion of females. It must be re- 

 membered that tropical BraconidiB are freely mimicked 

 (P. Z. S., 1902, p. 230), and that an experiment of Mr. Guy 

 A. K. Marshall's indicates that the latter are defended in 



