142 ME. C. N. BARKER 



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'' Do we not therefore go far beyond the scientific 

 use of tlie imagination, when, as in the practice 

 now so much in vogne, we not only conclude that 

 every well established colour and marking, if not ad- 

 A'antageous, is certainh' not disadvantageous in the 

 struggle for existence, but add the further postulate 

 that they are so by reason that animal vision appre- 

 ciates them in the same manner as is understood by 

 ourselves." 

 Monsieur Fabre's experiments with some of the moths, 

 notably that of the Notodontid Stauropus jagi, L. are 

 worth citing. This species is almost unknown to occur 

 •so far south as Provence, where M. Fabre resided. How- 

 •ever, he became possessed of an avid female, which he 

 kept in a closed box inside the liouse, and he was able to 

 watch the arrival of great numbers of males which all 

 came from the north on the Mistral that was then blow- 

 ing. No sense that we are cognisant of can account for 

 the arrival of these males from a great distance away 

 and wdth the wind. Tlie homing instinct of the Chalico- 

 doma bee is another illustration and equally inexplic- 

 able. With the hyper-sensitiveness of such organs as 

 these, mere superficial resemblances are not likely to be 

 deceptive to insects, so '^ Mimicry " must fall back upon 

 birds and such lower vertebrates as depend exclusively 

 on sight for its verification. Butterflies are the order of 

 insects that are most used to illustrate the theory, and 

 the depredations of birds are relied upon to prove its 

 truth. 



The fact that among some species of butterflies which 

 more or less resemble one another there are groups that 

 include both so-called distasteful and palatable species 

 has led up to the Miillerian hypothesis of '' Warning 

 Colours." Birds hunt by sight, and more often than not 

 ^capture their prey on the wing. It is therefore claimed 

 that the acquirement of certain distinctive colours and 

 patterns by several species of butterflies, among which 



