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by being like one another. This theory in contradistinction to 

 Bates' theory was called "Miillerian Mimicry." Since the theories 

 were promulgated no greater champion of their truths has arisen 

 than Professor E. B. Poulton. What he and others set themselves 

 to prove was, whether there was sufficient evidence that attacks 

 were made either by birds or other enemies in sufficient numbers 

 to account for the operation of Natural Selection in bringing about 

 these astonishing results. The method which was first put into 

 practice by Fritz Miiller to discover whether attacks were numerous, 

 and whether many different species were attacked, was applied to 

 the collecting of specimens with notches taken out of the wings, 

 presumably by birds or lizards. In the long and important 

 paper (Trans. Ent. Soc. Lond., 1902, p. 287-584) by Mr. G. A. K. 

 Marshall, on the " Bionomics of S. African Insects," there are 

 several plates with figures showing injuries. Some of these 

 are convincing and others most problematical, and here at once there 

 is ground for scepticism. Specimens with a single notch, that 

 is with only one wing notched, are no proof that the injury 

 was not self-inflicted by the insect flying through rough scrub or 

 what not. But specimens with notches in both forewings or both 

 hindwings, which coincide when the wings are folded, cannot be a 

 self-inflicted injury, as it must have been done while the insect was 

 settled. I think it, therefors, most unfortunate that cases which 

 afford strong, even if indirect, evidence, should have been mixed up 

 with examples which are meaningless. But, perhaps, before dis- 

 cussing this aspect of mimicry I should have broached the 

 question whether birds or other enemies were actually deceived 

 by the resemblance which we see. We shall probably never have 

 as much evidence on this point as to be absolutely certain that 

 enemies are largely deceived. From the human standpoint the case 

 cannot be answered satisfactorily. Dr. G. B. Longstaff (" Trans. 

 Ent. Soc. Lond.," 1908, pp. 607-673), in a paper entitled "Bionomic 

 Notes on Butterflies" has a section "Mimics in the Field deceiving 

 Man," and quotes how he has been deceived by cases of mimicry. 

 Even from the human standpoint I think we should insist on the 

 observer having no entomological knowledge beforehand. Man is 

 deceived in such cases m inverse proportion to the technical know- 

 ledge he has of the species concerned. One man would be deceived 

 where another with a greater technical knowledge would not be. 

 Observations of non-entomologists would be far more satisfactory. 

 It might be urged that if an entomologist can be deceived " a fortiori " 

 a non-entomologist would be. This is partly true, but one must be 



