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XXIII, On Milllcrian Mimicry and Dia2-)oscmati3m. A 

 Reply to Mr. G. A. K. Marshall. By F. A. 

 DixEY, MA., M.D,, Fellow of Wadham College, 

 Oxford. 



[Read October 21st, 1908.] 



In dealing with my friend Mr. G. A. K. Marshall's most 

 interesting paper (Trans. Ent. Soc. Lond., 1908, pp. 98-142), 

 a large part of -which consists of strictures upon views 

 which have from time to time been put forward by me, I 

 have in the first place to thank him for the courtesy which 

 allowed me to become acquainted with his criticisms before 

 these had been laid before the Society. I should wish 

 also to say at the outset that I am sincerely glad that 

 these criticisms have been offered. A theory is not likely 

 to meet with much acceptance until it has been well 

 scrutinised, and has run the gauntlet of adverse comment. 

 The propounder of a new idea ouglit to welcome any fair 

 objection that can be brought against his views. The 

 worst fate that can befall him is to be passed over in 

 silence ; and even if the attack upon his position should 

 prove successful, he has the satisfaction of knowing that at 

 least he has helped to stimulate enquiry, and that the 

 cause of truth has been the gainer. There is a reason for 

 which Mr. Marshall's objections are specially welcome. 

 We are likely to get from him as good a statement of his 

 side of the question as can be made, and if so doughty an 

 antagonist can be successfully answered, it is not likely 

 that the theory which he impugns will have to meet any 

 more formidable attack. 



Let me now see what points I have in common with 

 Mr. Marshall, and where exactly we diverge. 



In the first place, it is clear that he may be claimed as 

 a believer in Natural Selection and in the principle of 

 Mimicry, both in the Batesian and Miillerian sense. With 

 regard to the latter his words are : " There can be little 

 doubt that a good many cases of mimicry originally ad- 

 duced in support of Bates' theory must now be explained 

 on Miillerian lines " (p. 93). So far I am quite in accord 

 with him. Moreover, when he says that " the universal 



TRANS. ENT. SOC. LOND. 1908. — PART IV. (j AN. 1909) 



