THE COLOURS OF ANIMALS AND PLANTS 137 



Mimicry. 



Examples of mimicry are really cases of protective 

 colouring, but are only intelligible through knowledge 

 and appreciation of the value of the warning colour. 

 Alluring colours, such as those of the Mantis, which 

 simulates an orchid, may aptly be described as cases 

 of " wolves in sheep's clothing," while the cases of 

 mimicry may be considered as "asses in lions' 

 skins." 



Warning colours are conspicuous advertisements 

 of inedibility, and certain colours and groupings of 

 colours are usual, so that the lesson may be more 

 easily learnt. Black, white, red, and yellow, in 

 startling and striking contrasts, form the usual types 

 of warning colours. If these are successful — i.e., 

 generally recognised as signs of inedibility — it is clear 

 that other and different animals, which resemble 

 them sufficiently closely to be mistaken for them, 

 might benefit by the mistake, and escape. 



Certain butterflies, the best examples of which are 

 found among the Heliconidce, Danaidce, and Acrceidce, 

 are nauseous, slow-flying, gaudily-coloured insects, 

 having an unpleasant smell, and taking no pains to 

 conceal themselves. Alongside these occur edible 

 forms belonging to totally different genera and 

 families, each of which shows a striking resemblance 

 to one particular species of the protected butterfly ; 

 this being in many cases confined to the female, which 

 has greater need for protection. A large number 

 of cases of this mimicry are now known ; for instance, 

 Leptalis, a form allied to the common garden white, 



