RELATIONS AND SURROUNDINGS. 143 



Caterpillars oftentimes have an acrid or unpleasant 

 taste; but unless this is associated with a special odor or 

 color by which its enemies may recognize the fact before 

 they attack, it is not likely to prove of any great service 

 to the animal possessing it, since a single break in its soft 

 body made by the bill of a bird is likely to cause its death. 

 For similar reasons animals with stings are often highly 

 colored. The colors or other marks are, in these cases, 



FIG. 32. Protective mimicry of a drone bee (A), by 

 Folsom's Entomology.) 



drone fly (B). (From 



Questions on the Figure. Trace the points of similarity between 

 these insects. By reference to text-books determine the usual 

 differences between the flies and the bees. 



in the nature of warnings ; and the advantage comes from 

 the warning quite as much as from the sting or the bad 

 taste, because of the association of the two things in the 

 memory of the enemies. 



157. Mimicry. These facts give rise to the remarkable 

 phenomenon called mimicry. This term applies to those 

 cases where an edible or harmless animal has a similarity 

 of form or color to those that are dangerous or disagree- 

 able (Fig. 32) . It is believed by many students that such 

 mimicking animals gain a distinct advantage from this 

 similarity. It is necessary to remember that there is no 



