PROTECTIVE RESEMBLANCES, AND MIMICRY 365 



devils there is no light, the inky darkness being absolute. 

 This shining lure is therefore a most effective means of 

 securing food. 



285. Mimicry. Although the word mimicry could often 

 have been used aptly in the foregoing account of protective 

 resemblances, it has been reserved for use in connection 

 with a certain specific group of cases. It has been reserved 

 to be applied exclusively to those rather numerous instances 

 where an otherwise defenseless animal, one without poison- 

 fangs or sting, and without an ill-tasting substance in its 

 body, mimics some other specially defended or inedible ani- 

 mal sufficiently to be mistaken for it and so to escape 

 attack. Such cases of protective resemblance are called 

 true mimicry, and they are especially to be observed among 

 insects. 



In Fig. 225 are pictured three familiar American butter- 

 flies. One of these, the Monarch butterfly (Anosia plexip- 

 pus), is perhaps the most abundant and widespread butter- 

 fly of our country. It is a fact well known to entomologists 

 that the Monarch is distasteful to birds and is let alone by 

 them. It is a conspicuous butterfly, being large and chiefly 

 of a red-brown color. The Viceroy butterfly (Basilarchia 

 archippus), also red-brown and much like the Monarch, is 

 not, as its appearance would seem to indicate, a very near 

 relative of the Monarch, belonging to the same genus, but 

 on the contrary it belongs to the same genus with the third 

 butterfly figured, the black and white Basilarchia. All the 

 butterflies of the genus Basilarchia are black and white 

 except this species, the Viceroy, and one other. The Vice- 

 roy is not distasteful to birds ; it is edible, but it mimics the 

 inedible Monarch so closely that the deception is not de- 

 tected by the birds, and so it is not molested. 



In the tropics there have been discovered numerous 

 similar instances of mimicry by edible butterflies of inedi- 

 ble kinds. The members of two great families of butterflies 

 (Danaidae and Heliconidae) are distasteful to birds, and are 



