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viii] 



The results of Col. Manders' experiments upon misippus did 

 not seem to point uniformly towards inaria as the older form ; 

 for although the replacement of black by fulvous in the 

 apical region of the forewing, and the overspreading by 

 fulvous of the subapical white bar, supported this interpreta- 

 tion, the form and increased size of the bar itself suggested an 

 opposite one. It was to be observed that the bar is unusually 

 developed in the specimens which had been exposed to heat, 

 and that its basal margin (viz. that turned towards the cell) 

 possessed a remarkably bold zigzag outline. The shock of 

 the experiment had therefore in some respects carried the 

 individuals towards inaria, but in other respects had carried 

 them further away from it. 



With regard to Col. Manders' conclusion that the mimicry 

 was simply an accidental resemblance of no bionomic signi- 

 ficance, Prof. Poulton said that, if this were found to be 

 true of the female forms of //. misippus he did not see how the 

 theory of mimicry could be sustained at all. If these females, 

 in departing so immensely from the ancestral pattern preserved 

 by their male, had undergone these changes without relation 

 of any kind to the corresponding forms of the Danaine butter- 

 fly regarded as their model, he would be prepared to look on 

 all mimicry as accidental. He thought that Col. Manders 

 and those writers who agreed with him, expected too much 

 when they sought for evidence of the preferences of insecti- 

 vorous birds. Such inquiries were extraordinarily difficult and 

 wearisome, and a large px-oportion of the labour must inevit- 

 ably lead to negative results. Prof. Poulton felt convinced 

 that mimicry was an advantageous resemblance, not because 

 of the direct evidence but on account of the enormous and 

 ever-increasing mass of facts which received an interpreta- 

 tion on this hypothesis — for the same reasons, in fact, which 

 justified a belief in evolution itself. No other hypothesis as 

 yet proposed could be reconciled with the facts, and it was 

 extremely improbable that any hypothesis as yet unknown 

 would supply the interpretation of resemblances so numerous, 

 so wide-spread, so well known, and so much studied and 

 discussed. At the same time he was always urging his 



