MIMICRY IN INSECTS. 389 



protective resemblance in which a creature, otherwise defence- 

 less, imitates the form and colouring of another which has 

 some special means of protection, and thereby, as is probable, 

 escapes the pursuit of its enemies more easily than it could 

 without such a disguise. But here again the protection 

 obtained may benefit the pursuer as well as the pursued ; the 

 former by disguising it in the eyes of the alert pre}', the latter 

 by protecting a defenceless animal which mixes with the better- 

 armed species whose aspect it has borrowed. I need not insist 

 once more that the words here used must be taken in a figura- 

 tive sense, since it is clear that no animal can ever be capable 

 of designedly 'mimicking another. 



We owe the most important researches that have yet been 

 made on this interesting subject to the above-mentioned 

 judicious and acute travellers. No doubt we have long been 

 acquainted with insects living here, in Europe, which in form, 

 colour, and mode of flight bear a gi'eat resemblance to others of 

 difierent species; I may mention the Sesice among the butter- 

 flies, which greatly resemble bees, and owe to this resemblance 

 many of their specific names.'^' Formerly, little attention was 

 paid to this circumstance ; at most it was incidentally noted that 

 those butterflies were apparently protected by this resemblance, 

 but any attempt to explain this mimicry was never even 

 thought of before Darwin and Wallace ; and it was partly the 

 new views which, from Darwin, rapidly extended among zoo- 

 logists, and partly the vast number of striking examples of 

 such resemblances in tropical Brazil, which led Bates in the first 

 instance to examine the relations of these cases more exactly, 

 during his many years' residence in South America. 



A brief enumeration of the most important examples of 

 such mimicry will here be desirable ; but a complete list is ail 

 the less necessary because the labours of Wallace, Bates, and 

 Trimen are easily accessible, and popular essays on the subject 

 have appeared in many periodicals. Among the American 

 butterflies the species of Le.ptalis, Erycina, and Ithomia mimic 

 the HeliconiadoB, which are distinguished by a sharp and un- 

 pleasant smell. In the same way tlie Danaidce and Acrceidm of 

 the eastern regions of tropical America are protected by foetid 



