CHAP. IV 



Shifts for a Lv 



ivinz 



57 



9- Mimicry.— Mr. Poulton has carefully traced the transi- 

 tion from warning to mimetic appearance, and it is evident 

 that if hungry animals have been so much impressed with 

 the frequent association of unpalatableness and conspicuous 

 colours that they do not molest certain bright and nauseous 

 forms, then there is a chance that palatable forms may 

 also escape if they are sufficiently like those which are 

 passed by. The term mimicry is restricted to those cases 



Fig. 9. — Hornet {Pn'ocncnas) al ' ov e, and mimetic bug {Spinlgcr) beneatli. 

 (From Belt.) 



" in which a group ot animals in the same habitat, character- 

 ised by a certain type of colour and pattern, are in part 

 specially protected to an eminent degree (the mimicked), and 

 in part entirely without special protection (the mimickers) ; so 

 that the latter live entirely upon the reputation of the former." 

 The fact was " discovered by Bates in Tropical America 

 (1862), then by Wallace in Tropical Asia and Malaya 

 (1866), and by Trimen in South Africa (1870)"; while Kirby, 

 in 181 5, referred to the advantage of a certain fly being 

 like a bee, and of a certain spider resembling an ant. 



