182 THE MALAYAN PAP1LIONIDJZ AS 



have a very weak and slow flight, and do not seek 

 concealment, or appear to have any means of protec- 

 tion from insectivorous creatures. It is natural to 

 conclude, therefore, that they have some hidden pro- 

 perty which saves them from attack ; and it is easy 

 to see that when any other insects, by what we call 

 accidental variation, come more or less remotely to 

 resemble them, the latter will share to some extent in 

 their immunity. An extraordinary dimorphic form of 

 the female of Papilio Ormenus has come to resemble 

 the Drusillas sufficiently to be taken for one of that 

 group at a little distance ; and it is curious that I cap- 

 tured one of these Papilios in the Aru Islands hovering 

 along the ground, and settling on it occasionally, just 

 as it is the habit of the Drusillas to do. The resem- 

 blance in this case is only general ; but this form of 

 Papilio varies much, and there is therefore material 

 for natural selection to act upon, so as ultimately to 

 produce a copy as exact as in the other cases. 



The eastern Papilios allied to Polydorus, Coon, 

 and Philoxenus, form a natural section of the genus 

 resembling, in many respects, the ^Eneas-group of 

 South America, which they may be said to represent 

 in the East. Like them, they are forest insects, 

 have a low and weak flight, and in their favourite 

 localities are rather abundant in individuals ; and like 

 them, too, they are the objects of mimicry. We may 

 conclude, therefore, that they possess some hidden 

 means of protection, which makes it useful to other 

 insects to be mistaken for them. 



