ADAPTATION 



337 



is not to be regarded as a conscious act on the part of the imitator. 

 The steps by which the resemblance has been brought about are 

 unknown, but their history is doubtless similar to that of other 

 adaptations. 



Warning Adaptations. — Many animals provided with stings, 

 poison glands, or other effective means of defense, such as inedi- 



Fig. 191. — Mimicry. 



A, the monarch butterfly, Danaus menippe; B, the viceroy 

 butterfly, Basilarchia archippus. 



bility, are often conspicuously marked by what is known as 

 warning coloration. The orange- and black-banded coloration 

 of hornets and wasps are examples of this. Some brightly 

 colored caterpillars are avoided by birds because they are dis- 

 tasteful. The distinctive black and white of the fur of the skunk 

 is associated, in the minds of the experienced, with its powerful 

 scent glands. Poisonous amphibians and snakes are sometimes 

 gaudily colored or distinctively marked, but not always. Den- 



