Chai-. VII. ODOUK OF BUTTERFLIES. 299 



SO as to resemble the soil, leaf, or bark on which it 

 lives ; the resemblance sei'ving to conceal the creatures 

 from the prying eyes of their enemies ; or, if they are 

 predaceous species, serving them as a disguise to enable 

 them to approach their prey. When an insect, instead 

 of a dead or inorganic substance, mimicks another species 

 of its own order, and does not prey, or is not parasitic, 

 may it not be inferred that the mimicker is subject 

 to a persecution by insectivorous animals from which 

 its model is free ? Many species of insects have a most 

 deceptive resemblance to living or dead leaves ; it is 

 generally admitted, that this serves to protect them 

 from the onslaughts of insect-feeding animals who would 

 devour the insect, but refuse the leaf. The same might 

 be said of a species mimicking another of the same 

 order ; one may be as repugnant to the tastes of insect 

 persecutors, as a leaf or a piece of bark would be, and its 

 imitator not enjoying this advantage would escape by 

 being deceptively assimilated to it in external appear- 

 ances. In the present instance, it is not very clear 

 what property the Callithea possesses to render it less 

 liable to persecution than the Agrias, except it be that 

 it has a strong odour somewhat resembling Vanilla, 

 which the Agrias is destitute of This odour becomes 

 very powerful when the insect is roughly handled or 

 pinched, and if it serves as a protection to the Callithea, 

 it would explain why the AgTias is assimilated to it in 

 colours. The resemblance, as before remarked, applies 

 chiefly to the upper side ; in other species* it is equally 

 close on both surfaces of the wina's. Some birds, and the 



* Agi-ias Hewitsoniiis and Callithea Markii. 



